Class 12

MP Board Class 12th Biology Solutions Chapter 12 Biotechnology And its Application

Biotechnology And its Application NCERT Text Book Questions and Answers

Question 1.
Crystals of Bt toxin produced by some bacteria do not kill the bacteria themselves because:
(a) Bacteria are resistant to the toxin,
(b) Toxin is immature
(c) Toxin is inactive
(d) Bacteria enclose toxin in a special sac
Answer:
(c) Toxin is inactive. This is because it exists as protoxin, inactive form in bacteria.

Question 2.
What are transgenic bacteria? Illustrate using any one example.
Answer:
The bacteria whose DNA is manipulated to carry and express a foreign DNA is called transgenic bacteria. These microbes are used for producing important biochemicals. They have been synthesizing alcohol, enzymes, steroids and antibiotics. Example: Bacillus thuringiensis for Bt cotton, hirudin from transgenic Brassica napus seed. Hirudin is a protein which prevents blood clotting. Its gene was chemically synthesized and introduced in Brassica napus, in which hirudin accumulates in the seed from where it is extracted, purified and used as a medicine.

Question 3.
Compare and contrast the advantages and disadvantages of the production of genetically modified crops.
Answer:
Advantages:

• Crop plants can be made to grow fast and produce high yields through genetic modification.
• G.M crops increased the efficiency of mineral usage by plants.
• G.M crops helped to reduce post-harvest losses.
• It enhances the nutritional value of food, eg: Vitamin A enriched rice.
• Transgenic plants can produce pharmaceuticals like insulin, interferons blood clotting factors, hormones, etc.
• Resistance to viral diseases has been introduced in Tobacco, potato, tomato, and rice. Cry gene from bacillus has been introduced in Bt. cotton and Bt. Corn. Nematode infection has been overcome in some plants through RNA interference.
• Plants have been modified genetically to produced biodiesel and other commercial products.

Disadvantages:

• G.M. crops may cause problems in human health by supplying allergens and transferring antibiotic resistance markers.
  (b)These crops may come damage to the natural environment.
• Weedicide genes are being introduced into crop plants some of these crops may become superweeds
• Trans genes can be transferred from one plant to another plant, microbes, and even animals. It shall disturb the genetic set of organisms and cause ecological imbalance.
• Cry genes being introduced in crop plants can pass into wild vegetation. Insects feeding on pollen and other parts will be killed resulting in the destruction of pollination and disseminators.

Question 4.
What are Cry proteins? Name an organism which produces it How has man exploited this protein to his benefit?
Answer:
Cry proteins are toxic proteins (insecticidal proteins) secreted by Bacillus thuringiensis in crystal form during a particular phase of their growth. The toxin is coded by a gene called cry.

The genes encoding cry proteins called Bt-toxin genes were isolated from B. thuringiensis and incorporated into several crop plants such as Bt cotton, Bt com, etc. to provide resistance against insect pests.

Question 5.
What is gene therapy? Illustrate using the example of adenosine deaminase (ADA) deficiency.
Answer:
It is the therapeutic treatment of defective heredity by the introduction of healthy and functional gene which also silence the defective genes of an individual.
OR
The replacement of a nonfunctional or defective gene with a normal functional gene is called gene therapy. A person with defect in the gene for the enzyme adenosine deaminase (ADA) suffers with SC1D (Severe Combined Immuno Deficiency) The enzyme ADA is crucial for the immune system. Ideally gene therapy should be applied to the zygotes so that the progeny of defective individual also gets rid of effect. It is, however, generally applied to somatic cells where the defect occurs.

At first step towards gene therapy, lymphocytes from the blood of the patient are grown in a culture outside the body. A functional ADA cDNA (using a retrovirus vector) is then introduced into these lymphocytes which are subsequently returned to the patient. Since these cells are not immortal, the patient requires periodic infusion of such genetically engineered lymphocytes.

Question 6.
Diagrammatically represent the experimental steps in cloning and expressing a human gene (say the gene for growth hormone) into a bacterium like E. coli.
Answer:

Question 7.
Can you suggest a method to remove oil (hydrocarbon) from seeds based on your understanding of rDNA technology and chemistry of oil?
Answer:
Oil is synthesized by the condensation of 3 fatty acids with a molecule of glycerol. Fatty acids are formed through an enzyme complex called fatty acid synthetase. The oil from the seeds can be removed by preventing the synthesis of either glycerol or the enzyme lipase which catalyzes the synthesis of oil. It can be achieved by knocking out the genes coding for the enzyme lipase or the enzyme fatty acid synthetase.

Question 8.
Find out from the internet what is golden rice.
Answer:
Golden rice is a variety of rice produced through genetic engineering to biosynthesize β-carotene, a precursor of vitamin ‘A’ in the edible parts of rice. It is intended to produce a fortified food to be grown and consumed in areas with a shortage of dietary vitamin ‘A’.

Question 9.
Does our blood have proteases and nucleases?
Answer:
No, our blood does not contain enzymes proteases and nucleases. If these two enzymes were there in the blood, it causes the degeneration of blood cells and lining cells of blood cells.

Question 10.
Consult the internet and find out how to make orally active protein pharmaceuticals. What is the major problem to be encountered?
Answer:
For making any oral drug or nutritional supplement, the action of digestive enzymes has to be taken into account. Most of the antibiotics and vitamin supplements are made in capsule form to prevent the action of HC1 in the stomach. For protein preparation, the major source is groundnut shells. The protein extracted from the source is predigested so, as to make it absorbable by the digestive system.

Biotechnology And its Application Other Important Questions and Answers

Biotechnology And its Application Objective Type Questions

1. Choose the Correct Answer:

Question 1.
Triticum aestivum wheat is:
(a) Haploid
(b) Diploid
(c) Tetraploid
(d) Hexaploid.
Answer:
(c) Tetraploid

Question 2.
Man-made cereal is:
(a) Potato
(b) Triticale
(c) Triticum
(d) Sugarcane.
Answer:
(b) Triticale

Question 3.
Wheat grain is a:
(a) Fruit
(b) Seed
(c) Embryo
(d) Glume.
Answer:
(b) Seed

Question 4.
Removal of stamens from the flower during hybridization is called:
(a) Cutting
(b) Self-fertilization
(c) Emasculation
(d) Topnin.
Answer:
(c) Emasculation

Question 5.
New crop is:
(a) Triticale
(b) Rye
(c) Winged bean
(d) Wheat.
Answer:
(a) Triticale

Question 6.
Wheat used in bread is:
(a) Triticum aestivum
(b) Triticale
(c) All species of triticum
(d) Secale.
Answer:
(a) Triticum aestivum

Question 7.
Sonera-64 and Lerma roja-64 A are the varieties of:
(a) Wheat
(b) Rice
(c) Pea
(d) Maize.
Answer:
(a) Wheat

Question 8.
Haploid male plants can be produced by the culturing of:
(a) Filament
(b) Pollen grains
(c) Stamens
(d) Androecium.
Answer:
(b) Pollen grains

Question 9.
Ti plasmid which is used in genetic engineering is found in:
(a) Escherichia coli
(b) Bacillus thuringiensis
(c) Agrobacterium rhizogenes
(d) Agrobacterium tumefaciens.
Answer:
(d) Agrobacterium tumefaciens.

Question10.
Bt-Toxin is:
(a) Intercellutar lipid
(b) Intercellular crystal protein
(c) Extracellular crystal protein
(d) Lipid.
Answer:
(c) Extracellular crystal protein

Question 11.
The function of Bacillus thuringiensis is:
(a) Bio-metallurgy technique
(b) Bio-insecticides plant
(c) Bio-fertilizers
(d) Bio-mineralization process.
Answer:
(b) Bio-insecticides plant

Question 12.
Non-toxic crystal of Bt are made by bacteria but bacterias are not killed by own because:
(a) Non-toxic is immature
(b) Bacteria is immune resistant
(c) Non-toxic is inactive
(d) Bacteria has non-toxic sac.
Answer:
(c) Non-toxic is inactive

Question 13.
Genetic transfer through viruses is called:
(a) Sexduction
(b) Transduction
(c) Conjugation
(d) Transformation.
Answer:
(b) Transduction

Question 14.
Biopiracy is realated with:
(a) Discovery of biomolecules and genes
(b) Cultural knowledge
(c) Bio-research
(d) All of these.
Answer:
(d) All of these.

Question 15.
Golden rice is rich in which vitamin:
(a) Vitamin A
(b) Vitamin B
(c) Vitamin C
(d) Vitamin D.
Answer:
(a) Vitamin A

2. Fill in the Blanks:

1. …………………………. is the appropriation of another’s knowledge of use of biological resources.
2. A ……………………………. is a patent granted by the government to the inventor for biological entities.
3. ………………………………….. is a loosely used term for molecules that are present in organisms.
4. …………………………………… is a group of standards which is used in control of relations between our work and bio-diversity.
5. The production of product, its extraction and process is called ……………………………….

Answer:

1. Biopiracy
2. Biopatent
3. Bio-molecules
4. Bio-code of conduct
5. Downstream.

3. Match the Following:

Answer:

1. (b)
2. (d)
3. (a)
4. (c).

4. Answer in One Word/Sentence:

1. Give the name of first transgenic crop.
2. What is the name of insect-resistant protein which is transferred in Bt Cotton?
3. What is the name of first man-made insulin?
4. In which organism nif-genes are found?
5. Give the name of an antiviral protein.

Answer:

1. Tobacco
2. Cry protein
3. Humulin
4. Rhizobium
5. Interferon.

Biotechnology And its Application Very Short Answer Type Questions

Question 1.
Why is the gene encoding Cry protein inserted into crop plant?
Answer:
When the gene encoding cry protein inserted into a crop plant, the plant becomes resistant to insect pests.

Question 2.
Name the crops which are prepared with the help of biotechnology.
Answer:
Bt cotton, Bt maize, paddy, tomato, potato and soya been.

Question 3.
State the principle on which ELISA works?
Answer:
The principle is antigen-antibody interaction.

Question 4.
By which Bt toxin is coded?
Answer:
By cry genes Bt toxin is coded.

Question 5.
What is biopiracy?
Answer:
The use of bioresources by multinational companies and other organizations without proper authorization from the countries and people concerned.

Question 6.
Name the therapy which is the help of missing or defective ones in order to correct genetic disorders.
Answer:
Gene therapy.

Question 7.
What is the role of the organization GEACf.
Answer:
It checks (Delhi 2008)

• The validity of G.M crops
• The safety of introducing genetically modified organisms for public services.

Biotechnology And its Application Short Answer Type Questions

Question 1.
(a) Why is traditional knowledge related to bio-resources exploited? Give 2 reasons.
(b) Name 2 patents on Indian bio-resources that have been revoked.
Answer:
(a) Traditional knowledge is exploited to

• Develop modem applications of the resources
• Save time, effort, expenditure in the process of commercialization of bio-resources.

(b) The two Indian patents include

• Pesticide property of neem
• Healing and antiseptic property of turmeric.

Question 2.
Write down the advantage of GM Crops.
Answer:

Advantages of GM crops :

• Genetic modification has made crops more tolerant to abiotic stresses (cold, drought, heat, salt.)
• Viral resistance can be introduced.
• Over ripening losses can be reduced. Example: Flavr Savr Tomato.
• Enhanced nutritional value of food. Example: Golden Rice.
• Reduced reliance on chemical pesticides.

Disadvantages of GM crops :

• Transgenes in crop plants can endanger native species. Example: The gene for Bt toxin expressed in pollen may end natural pollinators such as honeybees.
• Weeds also become resistant.
• Products of transgenes may be allergic or toxic.
• They cause damage to the natural environment.

Question 3.
What is perfect agriculture? How is this method better than traditional method? Explain.
Answer:
Perfect agriculture is a method of agriculture which is sustainable, perfect and harmless. Green revolution and there after the production of agricultural crops has definitely increased due to use of new and high yielding varieties, development of irrigation facilities, increased irrigated area, use of fertilizers etc. but it results many problems such as loss of soil fertility, pollution of food and water and diseases. The resistance power of plants and human heings falls slowly. Food and water borne diseases affecting the health of human beings and animals.

All of these conditions and events taking place due to the modem commercial agriculture. Therefore, it would become necessary to develop a method of agriculture which would be free from above-mentioned demerits. This kind of agriculture is called to be as perfect or sustainable agriculture. Organic agriculture is the best example of perfect agriculture.

Question 4.
What is organic cropping? What are its basis?
Answer:
Organic agriculture: Organic agriculture is a method of agriculture which does not allow the use of synthetic fertilizers, pesticides, insecticides, weedicides, plant growth regulators, substances of animal origin and genetically modified bacteria. In this method biofertilizers, crop rotation methods are used to increase crop production and biopesticides are used to control insects and weeds.

Thus, organic farming is a holistic way of agriculture which tries to bridge the widening gap between man and nature. If has the commitment of meeting production needs on one hand and sustaining resources tand ecosystem function on the other hand. Thus, organic farming is an alternative agriculture production system which avoid or largely excludes the use of synthetic chemicals, fertilizers, pesticides and growth regulating hormones and live stock additives.

Basics of Organic agriculture :

• Organic agriculture is based on improvement of soil, plants, animals, man and global scinery and make it sustainable.
• Organic agriculture is based on those ecosystems and biocycles which utilize that organisms which would be promoted.
• It is based on the principle which are related with making pollution free environment and possibilities of life.
• It is also based on saving environment and health of present and future generations.

Question 5.
What is gene library?
Answer:
Gene library: Several clones of cells, each clone containing one or a few foreign genes representing almost all the genes of an organism is referred to as genes library. From this gene library it is possible to identify a clone containing gene of interest. In order to obtain gene library of an organism, its genome is first cut into smaller DNA fragments containing one or a few genes such as fragments can be cloned into a cell which may brfthat of bacteria, yeast, insects, plant or animal cell.

When such a cell multiplies to form a group of cells, all cells will contain the same foreign DNA fragment which was introduced initially. These cells which have similar foreign DNA fragment are referred to as a clone of cells. Several clones of cells each clone containing one or a few foreign genes are finally obtained and is called gene library.

Biotechnology And its Application Long Answer Type Questions

Question 1.
What is eugenics? Write importance of eugenics.
Answer:
Eugenics: The branch of biology which deals with the study of improvements of human race is called eugenics.
Importance:

• Development of selective reproduction in similar species.
• Transfer of genetic materials in various organisms.
• Development of GM food and GM crops.
• Gene cloning
• Gene therapy, etc.

Question 2.
Explain the following in brief:

1. Biopiracy,
2. Biopatent.

Answer:
1. Biopiracy: Some organizations and multinational companies exploit biological resources and genetic resources indigenous to a country without proper authorisation. This is called biopiracy. In fact it is illegal removal of biological material. The process of biopyracy involves collection of samples of biological sources, which can be done unnoticed. This biological material is then subjected to product development for use on a commercial scale.

Today a range of biological resources are facing biopiracy. It includes plants and animals, micro-organisms genetic materials etc. Western companies are getting great benefits from using the knowledge and biological resources of the third world communities.While the companies stand to make huge revenue from this process, the local communities are unrewarded and infact, may have to buy the products of these companies at high prices.
To check illegal exploitation of biological resources Government of India has signed the General Agreement on Tariffs and Trade (GATT), which opens country natural resources for foreign exploitation.

2. Biopatent : The protection given by government to an inventor of biological material to secure him for a specific time the exclusive right of manufacturing, exploiting, using and selling of an invention is called biopotent.

Today manufacturing companies are being granted patents for products and technologies that make of biological resources, such as plants and animals, genetic materials which was identified developed and used by farmers and indegenous peoples.

There is growing worldwide opposition to the granting of patents on biological materials such as genes, plants, animals and human. Farmers and indegenous peoples are outaged that’ plants that they developed are being ‘hijacked’ by companies. Groups are diverse as religious leaders, parliamentarians and environment NGOs are intensifying campaign against corporate patenting of living things.

Question 3.
Describe by giving one example for each of why transgenic animals are produced.
Answer:

• Transgenic animals are designed to allow the study of how genes are regulated and how they affect the normal functions of the body and its development
  eq: Information is obtained as to how insulin has a role as growth factor
• They are designed to increase our understanding as to how genes could control the development of disease, they serve as models of human disease.
• They produce useful biological compounds created by introducing a portion of the DNA that code for the products.
  eg: a-1 antitrypsin is produced for treating emphysema
• They are being developed to test the safety vaccines, eg: Polio vaccines has been tested on mice
• Transgenic animals with more sensitivity to toxic substance are being developed to test the toxicity of drugs.

MP Board Class 12th Biology Solutions

MP Board Class 12th Biology Solutions Chapter 10 Microbes in Human Welfare

Microbes in Human Welfare NCERT Text Book Questions And Answers

Question 1.
Bacteria cannot be seen with the naked eyes, but these can be seen with the help of a microscope. If you have to carry a sample from your home to your biology laboratory to demonstrate the presence of microbes under a microscope, which sample would you carry and why?
Answer:
Curd can be used as a sample for the study of microbes. Curd contains numerous Lactic Acid Bacteria (LAB) or Lactobacillus. These bacteria produce acids that coagulate and digest milk proteins. A small drop of curd contains millions of bacteria, which can be easily observed under a microscope.

Question 2.
Give example to prove that microbes release gases during metabolism.
Answer:
The dough of dosa and idli is fermented by bacteria while the dough of bread is fermented by yeast. The puffed-up appearance is due to CO₂ gas production.

Question 3.
In which food would you find lactic acid bacteria? Mention some of their useful applications.
Answer:
Lactic acid bacteria can be found in curd. It is this bacterium that promotes the formation of milk into curd. The bacterium multiplies and increases its number, which converts the milk into curd. They also increase the content of vitamin B₁₂ in curd.

Lactic acid bacteria are also found in our stomach where it keeps a check on the disease-causing microorganisms.

Question 4.
Name some traditional Indian foods made of wheat, rice, and Bengal gram (or their products) which involve the use of microbes.
Answer:

• Bhatura, Bread, Jalebi (wheat).
• Dosa, Idli (Rice)
• Karhi (Bengal gram).

Question 5.
In which way have microbes played a major role in controlling diseases caused by harmful bacteria?
Answer:
Several microorganisms are used for preparing medicines. Antibiotics are medicines produced by certain microorganisms to kill other disease-causing microorganisms. These medicines are commonly obtained from bacteria and fungi. They either kill or stop the growth of disease-causing microorganisms.

Streptomycin, tetracycline and penicillin are common antibiotics. Penicillium notatum produces the chemical penicillin, which checks the growth of staphylococci bacteria in the body. Antibiotics are designed to destroy bacteria by weakening their cell walls.

Question 6.
Name any two species of fungus, which are used in the production of antibiotics.
Answer:
Antibiotics are medicines that are produced by certain microorganisms to kill other disease-causing microorganisms. These medicines are commonly obtained from bacteria and fungi. The species of fungus used in the production of antibiotics are :

Question 7.
What is sewage? In which way can sewage be harmful to us?
Answer:
Sewage is the municipal waste-water collected from city or townhomes, that contains a toilet, bathroom, and kitchen waste.
It contains large amounts of organic matter and many pathogenic microbes which are harmful to humans as they can cause many diseases like cholera, typhoid, polio.

Question 8.
What is the key difference between primary and secondary sewage treatment?
Answer:
Differences between Primary and Secondary sewage treatment:

Question 9.
Do you think microbes can also be used as source of energy? If yes, how?
Answer:
Yes, microbes can be used as a source, of energy. Bacteria such as; Methane bacterium is used for the generation of gobar gas or biogas. The generation of biogas is an anaerobic process in a biogas plant, which consists of a concrete tank (10-15 feet deep) with sufficient outlets and inlets. The dung is mixed with water to form the slurry and thrown into the tank.

The digester of the tank is filled with numerous anaerobic methane-producing bacteria, which produce biogas from the slurry. Biogas can be removed through the pipe which is then used as a source of energy, while the spent slurry is removed from the outlet and is used as a fertilizer.

Question 10.
Microbes can be used to decrease the use of chemical fertilizers and pesticides. Explain how this can be accomplished.
Answer:
Chemical fertilizers are used to increase availability of minerals while pesticides are economically harmfull and toxic to human being, cattles. This disturbs biological environment. Microbes used as fertilizers (bio fertilizes) and pesticide (biopesticide) are not harmful to ecology and humans. Organic farming uses them and provides increased production.

Question 11.
Three water samples namely river water, untreated sewage water and secondary effluent discharged from a sewage treatment plant were subjected to BOD test The samples were labelled A, B and C; but the laboratory attendant did not note which was which. The BOD values of the three samples A, B, and C were recorded as 20mg/L, 8 mg/L and400mg/L, respectively, which sample of the water is most polluted? Can you assign the correct label to each assuming the river water is relatively clean ?
Answer:

• The BOD values of the three samples A, B and C were recorded as 20 trig/L 8 mg/L and400mg/L.
• Greater the BOD of wastewater more is its polluting potential. So, sample C is more polluting as compared to sample A.
• Hence, sample A is the secondary effluent, sample B is river water and sample C is untreated sewage water.

Question 12
Find out the name of microbes from which cyclosporine(animmuno-suppressive drug) and statins (blood cholesterol-lowering agents) are obtained.
Answer:

• Cyclosporin A from Trichoderma polysporum
• Statins from yeast Monascus purpureus.

Question 13.
Find out the role of microbes in die following and discuss it with your teacher,
(a) Single Cell Protein (SCP)
(b) Soil.
Answer:
(a) Single Cell Protein (SCP) refers to harmless microbial cells that can be used as an alternate source of good protein.

Just like mushrooms (a fungus) is eaten by many people and yeast is used by athletes as a protein source; similarly, other forms of microbial cells can also be used as food rich in protein, minerals, fats, carbohydrate and vitamins.

Microbes like SpiruMna and Methylophilus methylophus are being grown on an industrial scale on materials containing starch like waste water from potato processing plants, straw, molasses, animal manure and even sewage. These single cell microbes can be used as source of proteins.

(b) Microbes play an important role in organic farming which is done without the use of chemical fertilizers and pesticides. Bio-fertilizers are living organisms which help increase the fertility of soil. It involves the selection of beneficial microorganisms that help in improving plant growth through the supply of plant nutrients. Bio-fertilizers are introduced in seeds, roots or soil to mobilize the availability of nutrients. Thus, they are extremely beneficial in enriching the soil with organic nutrients.

Many species of bacteria and cyanobacteria have the ability to fix free atmospheric nitrogen, Rhizobium is a symbiotic bacteria found in the root nodules of leguminous plants. Azospirillium and Azotobocter are free living nitrogen fixing bacteria, whereas Anabena, Nostoc and Oscillitoria are examples of nitrogen-fixing cyanobacteria. Bio-fertilizers are cost effective and eco-freindly.

Microbes can also act as bio-pesticides to control insect pest in plants. An example of bio-pesticides is Bacillus thuringiensis, which produces a toxin that kills the insect pests. Dried bacterial spores are mixed in water and sprayed in agricultural fields. When larvae of insects feed on crops, these bacterial spores enter the gut of the larvae and release toxins, thereby it. Similarly, Trichoderma are free living fungi. They live in the roots of higher plants and protect them from various pathogens. Baculoviruses is another bio-pesticides that is used as a biological control agent against insects and other arthropods.

Question 14.
Arrange the following in the decreasing order (most important first) of their importance, for the welfare of human society. Give reasons for your answer. Biogas, Citric arid, Penicillin and Curd.
Answer:
Penicillin > Biogas > Curd> Citric Acid.

• Penicillin an antibiotic cures bacterial diseases.
• Biogas is source of energy and pollution-free fuel.
• Curd easily digestible vitamin-rich milk preparation.
• Citric Acid used as preservatives.

Question 15.
How do biofertilizers enrich the fertility of the sofl?
Answer:
Bio-fertilizers are living orgainsms which help in increasing the fertility of soil. It involves the selection of beneficial microorganisms that help in improving plant growth through the supply of plant nutrients. These are introduced to seeds, roots, or soil to mobilize the availability of nutrients by their biological activity. Thus, they are extremely beneficial in enriching die soil with organic nutrients.

Many species of bacteria and cyanobacteria have the ability to fix free atmopheric nitrogen. Rhizobium is a symbiotic bacteria found in the root nodules of leguminous plants. Azospirillium and Azotobocter are free living nitrogen-fixing bacteria, whereas Anabena, Nostoc and Oscillitoriasie. examples of nitrogen-fixing cyanobacteria. Bio-fertilizers are cost effective and eco-friendly.

Microbes in Human Welfare Other Important Questions And Answers

Microbes in Human Welfare Objective Type Questions

1. Choose the Correct answers:

Question 1.
A milk product which is sours as buttermilk:
(a) Paneer
(b) Curd
(c) Yoghurt
(d) None of these.
Answer:
(b) Curd

Question 2.
Tetracydineisfoundin:
(a) From Strepto ramosus
(b) From Strepto oreofashion
(c) From Strepto freddy
(d) From Strepto nodosum.
Answer:
(a) From Strepto ramosus

Question 3.
Clostridium, Azotobacter, Rizobium increase fertility through:
(a) From nitrogen fixation
(b) From denitrogenation
(c) From imulsification
(d) From vitamin.
Answer:
(a) From nitrogen fixation

Question 4.
The vitamin obtained from Streptomyces olivaceus and Bacillus megaterium:
(a) Vitamin C
(b) Vitamin D
(c) Vitamin E
(d) Vitamin B₁₂
Answer:
(a) Vitamin C

Question 5.
Which of the following is used in the treatment of T.B. leprosy pneumonia:
(a) Bacteriophage
(b) Only virus
(c) Only bacteria
(d) Fungi.
Answer:
(d) Fungi.

Question 6.
How is the virus used in biotechnology and microbiology:
(a) In form of medicine
(b) In form of vector
(c) In water treatment
(d) All of these.
Answer:
(b) In form of vector

Question 7.
Which of the following is useful in bakery product like Indian bread, biscuit, and other product:
(a) Virus
(b) Bacteria
(c) Yeast
(d) Protozoan.
Answer:
(c) Yeast

Question 8.
Which vitamin is found in yeast:
(a) Vitamin C
(b) Vitamin D
(c) B complex
(d) Vitamin A.
Answer:
(c)B complex

Question 9.
Which medicine is obtained from Strepto ramosus:
(a) Terramycine
(b) Niomycine
(c) Erythomycine
(d) Actidine.
Answer:
(a) Terramycine

Question 10.
Nitrosomonas and Nitrobacter bacteria is:
(a) Denitrifying
(b) Nitrifying
(c) Azotobactor
(d) Haimoneproduces.
Answer:
(b) Nitrifying

Question 11.
Through lactic acid bacteria the transformation from milk to curd increases the amount of which vitamin:
(a) Vitamin C
(b) Vitamin D
(c) Vitamin B₁₂
(d) Vitamin E.
Answer:
(c) Vitamin B₁₂

Question 12.
Methanogen is not found in:
(a) Rhumen of cattles
(b) Biogas plant
(c) Bottom of paddy farm
(d) Cell wall of the bacteria.
Answer:
(d) Cell wall of the bacteria.

Question 13.
Water is free from this primary treatment of sewage:
(a) Dissolve impurities
(b) Suspended particle
(c) Harmfull substance
(d) Harmfull Bacteria.
Answer:
(b) Suspended particle

Question 14.
B.O.D. of waste water is calculated by:
(a) Total organic matter
(b) Bio-degradable organic matter
(c) Releasing of oxygen
(d) Consumption of oxygen.
Answer:
(d) Consumption of oxygen.

Question 15.
The technique of biogas production in India developed with the help of these:
(a) Gas Authority of India V
(b) Oil and Natural Gas Aayog
(c) Indian Agricultural Statistics Research Institute.
(d) Indian Oil Corporation.
Answer:
(c) Indian Agricultural Statistics Research Institute.

Question 16.
Free-living fungus Try coderma should be used in:
(a) Kill pests
(b) Biological control of plant diseases.
(c) In control of caterpillar of a butterfly
(d) Formation of Antibiotics.
Answer:
(b) Biological control of plant diseases.

Question 17.
Mycorrhiza does not help the host plant in:
(a) Increasing the phosphorus capturing capacity in host plant
(b) Increasing dryness capturing capacity in host-plant
(c) Increase the immunity of root from pathogen
(d) Increase the immunity from insects in host-plant.
Answer:
(a) Increasing the phosphorus capturing capacity in host plant

2. Fill in the blanks:

1. The branch of biology dealing with the structure and modes of existence of microscopic organisms is called ………………………
2. The bacteria of …………………….. species is used by making paneer.
3. Nitrosomonas and Nitrobacter is ……………………….. bacteria.
4. ……………………. bacteria is used in the vinegar industry.
5. Pectinase enzyme is made by ……………………….. species.
6. Size of microorganism is lesser than ……………………………. mm.
7. Curd is made by …………………………… bacteria.
8. By the adding of fruit or fruit essence into cheese which is made from milk. The substance is called ………………………..
9. The curdled milk which is made from milk is called ………………………
10. Antibiotics that are active chiefly against gram-negative bacteria is called ………………………………

Answers:

1. Microbiology
2. Lactobacillus
3. Nitrifying
4. Acetobacteraceti
5. Clostridium
6. 0.1
7. Lactobacillus
8. Yoghurt
9. Raw curded milk
10. Polymyxin.

3. Match the Following:

Answers:

1. (d)
2. (a)
3. (b)
4. (c)

Answers:

1. (c)
2. (d)
3. (e)
4. (a)
5. (b)

Answers:

1. (d)
2. (a)
3. (b)
4. (c)

4. Answer in One Word/Sentence:

1. Name the fish used to control mosquitoes.
2. Name the two free-living bacteria found in soil.
3. What is called the control of insects and weeds?
4. Name symbiotic and non-symbiotic nitrogen-fixing bacteria.
5. Write the full name of IPM.
6. Give the name of one pesticide.
7. How does biofertilizer act as fertilizer? (CBSE2004)
8. What is yoghurt?
9. What is sufu?
10. Name the enzyme which is used to dissolve the blood clot.
11. What is interferon?

Answers:

1. Gambusia
2. Azotobacter, Clostridium
3. Pest control and weed control
4. Rhizobium, Azotobacter
5. Integrated pest management
6. D.D.T.
7. By nitrogen fixing
8. Milk product
9. Chinese food
10. Streptokinase
11. Antiviral protein

Microbes in Human Welfare Very Short Answer Type Questions

Question 1.
Name useful microorganisms.
Answer:
Some useful microorganisms are bacteria, fungi and viruses.

Question 2.
What changes are brought about in milk by LAB?
Answer:
LAB produces acids that coagulate and partially digest the milk proteins.

Question3.
Which products are found by bacteria in dairy farms?
Answer:
Curd, paneer, butter, yoghurt, butter are milk are found in dairy farms in the help of Lactobacillus species and Streptococcus species.

Question 4.
What are prions?
Answer:
Prions are proteinaceous infectious agents

Question 5.
What is microbiology?
Answer:
The branch of science that deals with microorganisms.

Question 6.
Name the fungus which produce these products:

1. Cytric acid,
2. Vitamin B₂
   

Answer:

Question 7.
What is yoghurt?
Answer:
Yoghurt is a semi-solid sourish food prepared from milk fermented by added bacteria.

Question 8.
Name the organism used for the preparation of Swiss cheese?
Answer:
Propioni bacterium sharmani.

Question 9.
Who discover Penicillin?
Answer:
Alexander Fleming.

Question 10.
What is the scientific name of brewer’s or baker’s yeast? (AI2009)
Answer:
Saccharomyces cerevisiae.

Question 11.
Which organism is used for making citric acid in industries?
Answer:
Aspergillus niger.

Question 12.
Name the free-living nitrogen-fixing bacteria in the soil.
Answer:
Azospirillum and Azotobacter.

Question 13.
What bacteria is found in anaerobic sludge.
Answer:
Methanogene.

Question 14.
What is ladybird?
Answer:
It is an insect which is used as biocontroler for Aphid control.

Question 15.
What is the full form of IPM ?
Answer:
Integrated Pest Management.

Question 16.
What is biological control of Pests?
Answer:
It is the method of controlling pest in agriculture, that relies on natural predation rather than, the introduced elements.

Question 17.
Which mineral is absorbed by mycorhiza, this mineral is not should be absorbed by plant roots?
Answer:
Phosphorus.

Question 18.
Name the microorganism which is changed to milk in curd.
Answer:
Lactobacillus spp.

Question 19.
Which fungi are used in the treatment of plant due to biological control?
Answer:
Trichoderma spp.

Question 20.
Which bacteria is used in swiss paneer?
Answer:
Propionibacterium shermanii.

Question 21.
Which paneer is completed by the growth of fungus?
Answer:
Roquefort cheese.

Question 22.
Name two alcoholic drink which is formed by without distillation.
Answer:
Bear and Wine.

Question 23.
Name two alcoholic drink which are formed by distillation.
Answer:
Whiskey and Rum.

Question 24.
What is the full form of BOD?
Answer:
Biochemical or Biological Oxygen Demand.

Question 25.
Name the bacteria which play an important role in N2 fixation in the soil.
Answer:
Spirullina.

Question 26.
Name an infectious agent which has neither DNA nor RNA.
Answer:
Prion.

Microbes in Human Welfare Short Answer Type Questions

Question 1.
What is paneer ? Give its preparation method.
Answer:
Paneer is a milk product, which has 20-30% protein first filtered and the milk in thin cloth than heat on 60°C at 30 minutes and heat on 75°C at 15 second later it cold till 30°C. Add some quantity of lactic acid bacteria Streptococcus lactis, Streptococcus cremoris and enzyme renin. By this fat and casein protein is detached from milk after 45 minutes this mixture became solid. Now, they are cut into small pieces and boild in hot water, when it starts floating, they are separated and squeezed. Then they areput in salt water for treating. Paneer is now ready.

Question 2.
What is the utilization of Bacteria in agriculture?
Answer:
Uses of Bacteria: Uses of bacteria for agriculture are as follows:

1. They increase soil fertility due to the decomposition of dead organisms.
2. They increase soil fertility through nitrogen fixation in soil. ‘
3. Green-blue algae are used in the form of fertilizers.
4. They are balancing the number of mineral salts.

Question 3.
How are the bacteria used in vinegar industry?
Answer:
Fermentation of sugar by yeast in vinegar industry. Due to this manner, wine is prepared. This ethyl alcohol abandoned indirect air for much time now, it is changed in vinegar.

Question 4.
Name five fungi which are given antibiotics.
Answer:
Name the fungi are as follows:

Question 5.
Name five bacteria which produce antibiotics.
Answer:
Name the bacteria are as follows:

Microbes in Human Welfare Long Answer Type Questions

Question 1.
Write a short note Cryprotein and its agricultural use. (CBSE 2006)
Answer:
Cryprotein is a potentially toxic chemical that is produced in pro toxin crystalline endotoxin state by bacterium Bacillus thurigenes. It can be extracted from the bacterium. The protein is also present in spores of the bacterium. The commercial product is called sporein, depel, biostol and thurigenesis. It is sprayed over the crop. As the protein reaches the midgut of the insect.it is converted into the toxic state by alkaline pH and digestive enzyme. The toxic binds to specific receptors present on epithetial cells, creates pores and ruptures the cells causing death of the insects.

There are several types of Cryproteins specific to different types of insects. The gene for cry protein called cry has been incorporated in some crop plants to provide resistance to insect pests. Such genetically modified crop plants are called Bt (after Bacillus thurigenesis) crops, example Bt cotton.

Question 2.
Write economic importance of Fungi.
Answer:
Following are the economic importance of fungi:

1. As food: Mushrooms like Agaricus, Lycoperdon, Romaria, Clavasia are used as food. These mushrooms contain about 50% protein. Morchella is also used as food.
2. As medicine: Fungi provides various types of antibiotics as for example Penicillin, Griseofulvine, Citrinine, Clavicine, Gliotoxine, etc. Which are used in the treatment of disease.
3. The fertility of soil: Many fungi species increase the soil fertility by decomposition of dead organic matter.
4. Nitrogen fixation: Many fungus like Rhodotorula increases the soil fertility by nitrogen fixation.
5. In the bakery industry: Yeast cells are used in bakery to produce spongy breads.
6. In the wine industry: Yeast cells contain the enzyme zymase which ferments sugar into alcohol.
7. In the chemical industry: Many fungi species are used in the production of various types of acid like citric acid.
8. In the cheese industry: Fungus Penicillium roqueforti is used in the preparation of camembert type of cheese from milk.

Question 3.
Explain the uses and types of viruses.
Answer:
Uses of Viruses:

• As it forms a link between non-living and living thus, it helps us to understand organic evolution.
• Cyanophage (Blue-green algae viruses) are used to destroy blue-green algae grown in different areas.
• Bacteriophages are used as biocides to destroy many harmful bacterias present in a polluted area.

For example, Water of the river Ganga always remain pure and dean in bottles year after year due to presence of bacteriophage’ in it.
Nucleic acids of viruses: Viruses generally contain only one type of nucleic acid DNA or RNA. DNA is found in animal viruses, whereas RNA is found in plant viruses.

Human Immuno Virus (HIV):
It causes AIDS disease in humans. Full form of AIDS is Acquired Immuno Deficiency Syndrome. This virus destroys the immune system of the body, thus, the patient of AIDS suffers from a number of diseases at a time, and at last he dies.
This virus is found surrounded by protein and a ring of RNA is found at the centre. Whole-body of virus is surrounded by a covering of glycoprotein.
Type of Viruses: On the basis of a host infected, viruses are grouped into the following four groups:

1. Animal viruses: Viruses which infect animals are called animal viruses. These viruses contain DNA as genetic material.
2. Plant viruses: Viruses which infect plants are called plant viruses. These viruses contain RNA as genetic material.
3. Cyanophages: Viruses that infect blue-green algae are called cyanophages. These viruses contain RNA as genetic material.
4. Bacterial viruses or Bacteriophages: Viruses that infect bacteria are called bacteriophages. They contain DNA as genetic materials.

MP Board Class 12th Biology Solutions

MP Board Class 12th Biology Solutions Chapter 8 Human Health and Disease

Human Health and Disease NCERT Textbook Questions and Answers

Question 1.
What are the various public health measures which you would suggest as safeguard against infectious disease ?
Answer:
The common preventive measures are as follows :

• Education: People should be educated about communicable diseases to protect, themselves from such diseases.
• Vaccination: People should get vaccination on time to avoid infection.
• Sanitation: The sanitation condition should be improved to avoid infection from polluted water, contaminated food, etc.
• Eradication of vectors: The breeding places of vectors should be destroyed. adult vectors should be killed by suitable methods.
• Sterilization: The patient’s surroundings and articles of use should be completely sterilised so as to reduce the chances of infection.

Question 2.
In which way has the study of biology helped us to control infectious diseases?
Answer:

• Helps to properly diagnose the problem and treat them
• Life cycle, host, reservoir, vectors, agents all can be studied and identified
• Mechanism of transmission of pathogens to humans are known
• Protective measures against catching the diseases are suggested.
• Vaccines and medicines against pathogen are worked out.

Question 3.
How does the transmission of each of the following diseases take place :
(a) Amoebiasis
(b) Malaria
(c) Ascariasis
(d) Pneumonia.
Answer:
(a) Amoebiasis : Through faecal-oral route.
(b) Malaria : Through the bite of female Anopheles mosquito.
(c) Ascariasis : Through taking contaminated food and water.
(d) Pneumonia : Droplets from the sputum of the patient.

Question 4.
What measure would you take to prevent water-borne diseases?
Answer:

• All water resources, pools, tanks to be cleaned regularly and prevent this contamination. Only properly treated water should be added to it.
• Use only purified and disinfected water for drinking.
• Prevent passage of sewage and garbage into water bodies

Question 5.
Discuss with your teacher what does ‘a suitable gene’ means, in the context
of DNA vaccines.
Answer:
The term ‘suitable gene’ refers to that specific segment of DNA which forms immunogenic protein, such genes can be cloned and then integrated with vector for introducing into an individual to be immunised for certain disorder producing a particular vaccine against the pathogens.

Question 6.
Name the primary and secondary lymphoid organs.
Answer:

• Primary lymphoid organs – Organs where B & T – lymphocytes are formed, mature, and require antigen-specific receptors – Bone marrow and thymus.
• Secondary lymphoid organs – place or residence of nature lymphocytes – lymph nodes, spleen, tonsils, Peyer’s patches, and mucosal surfaces.

Question 7.
The following are some well-known abbreviations, which have been used in this chapter. Expand each one to its full form :

1. MALT
2. CMI
3. AIDS
4. NACO
5. HIV.

Answer:

1. MALT: Mucosa Associated Lymphoid Tissue.
2. CMI: Cell-Mediated Immunity.
3. AIDS: Acquired Immune Deficiency Syndrome.
4. NACO: National AIDS Control Organisation.
5. HIV: Human Immunodeficiency Virus.

Question 8.
Differentiate the following and give examples of each :
(a) Innate and Acquired immunity.
(b) Active and Passive immunity.
Answer:
(a) Differences between Innate and Acquired immunity :

(b) Differences between Active and Passive immunity:

Question 9.
Draw a well-labeled diagram of an antibody molecule.
Answer:

Question 10.
What are the various routes by which transmission of Human Immuno-deficiency Virus takes place?
Answer:

• Sexual contact with infected person.
• Through blood transfusion.
• By sharing infected needles in case of intravenous drug abusers.
• From mother to child through the placenta.

Question 11.
What is the mechanism by which the AIDS virus causes a deficiency in the immune system of the infected person?
Answer:
The virus enters macrophages after getting into the body of an individual where RNA forms viral DNA by reverse transcription. The viral DNA gets incorporated in the host cell’s DNA and directs the infected cells to produce viral copies. The newly produced virus particles attack helper T-cells and thus, the number of T-cells decrease. Since, the helper T-cells are essential for functioning of immune system, the person suffers from various diseases due to dificient immune system.

Question 12.
How is a cancerous cell different from a normal cell?
Answer:
Normal cells remain adhered to one another. They have a definite life span. As some old cells die, they are replaced by new cells which arise by cell division and differentiation. Cancerous cells:- Whenever there is a breakdown of any regulatory mechanism, a cell develops the ability to undergo uncontrolled repeated division forms a clone at cells.

There is no adherence. The cells slip past one another forming a mass of undifferentiated cells called neoplasm or tumour. Tumour results in pressing of surrounding normal cells and tissues causing discomfort and disruption of their functioning.

Question 13.
Explain what is meant by metastasis?
Answer:
Metastasis is the spread of cancerous cells through migration from one tissue to other tissue and organs resulting in formation of secondary tumour. Malignant tumour is a mass of proliferating cells called neoplastic cells. They grow rapidly and invade surrounding unaffected normal cells or tissues. Cells get sloughed off from such tumour and migrate to distant sites through blood. A new place of infection is thus, established and a new tumour is formed. This property is called metastasis.

Question 14.
List the harmful effects caused by alcohol/drug abuse.
Answer:

• Addicts show reckless behaviour vandalism and violence. Self-confidence lost
• Neural and neuromuscular junctions are effected.
• Addiction disturbs peristalsis and secretion of digestive enzymes.
• Disturbs digestive and nervous systems leads to frequent nausea and vomiting.
• Effects on cardiovascular system.
• Damage to liver causes cirrhosis.
• Insufficiency develops in reproductive system.

Question 15.
Do you think that friends can influence one to take alcohal / drugs? If yes, how may one protect himself / herself from such as influence?
Answer:
Yes, friends can influence one to take drugs and alcohol. A person can take the following steps for the prevention of themself against drug abuse :

• By avoiding under peer pressure as everyone has their own field of interest which should be respected by there teachers and family. One should not experiment with alcohal for curiosity and fun.
• Avoid the company of friends who take drugs.
• Seek help from parents and peers. A child should not pushed beyond his/her threshold
  limits.
• Take proper knowledge and counselling about drug abuse. Devolve your energy in other extra-curricular activities.
• Seek immediate professional and medical help from psychologists and psychiatrists if symptoms of depression and frustration become apparent.
• Get rid of the problem completely and lead, perfectly normal life by increasing their will power.

Question 16.
Why is that once a person starts taking alcohol or drugs, it is difficult to get rid of this habit ? Discuss it with your teacher.
Answer:
It is difficult to get rid of this habit, because these substances are addictive and one starts having unpleasant feelings or withdrawal symptoms like nausea, vomiting, diarrhoea, shivering, muscle twitching, excessive perspiration, muscular and abdominal cramps. Mind loses control and all one can think of is taking the addictive substance. That is why resisting the temptation/pressure for the first time is the only way to avoid getting into the addictive habit and committing a slow suicide.

Question 17.
In your view what motivates youngsters to take to alcohol or drugs and how can this be avoided?
Answer:
Probably the ‘motivation’ comes from :

• Curiosity to experience the effect.
• Foolishness to try to prove oneself in front of peers.
• Wrongly taking it as an excuse to escape from reality.
• Wrong thinking that one-time ‘try’ is not going to do any harm.

But youngsters who, are strong-willed, who understand its ill effects and who are satisfied with their academic and other achievements and who don’t want to waste their precious life, don’t fall for this kind of ‘Motivation’.

Human Health and Disease Other Important Questions and Answers

Human Health and Disease Objective Type Questions

1. Choose the correct Answers :

Question 1.
Useful vaccines from the protection of Polio, Diphtheria and Tetanus :
(a)B.C.G.
(b) D.RT.
(c) M.M.R.
(d) S.T.D.
Answer:
(b) D.RT.

Question 2.
After the disease, immunity produced in the body is called:
(a) Active immunity
(b) Inactive immunity
(c) Both (a) and (b)
(d) None of these.
Answer:
(a) Active immunity

Question 3.
Cancer is related to :
(a) Irregular growth of tissues
(b) Ageing
(c) Irregular division of tissues
(d) None of these.
Answer:
(a) Irregular growth of tissues

Question 4.
Concept against smallpox vaccination is:
(a) W.B.Cs. received from animals
(b) Antigen obtained from other animals
(c) Of Antigens
(d) To weak the smallpox virus.
Answer:
(d) To weak the smallpox virus.

Question 5.
Syphilis is a sexually transmitted disease which is caused by:
(a) Pastrulla
(b) Leptospira
(c) Treponema pallidum
(d) Vibrio.
Answer:
(c) Treponema pallidum

Question 6.
Antibody is a:
(a) A molecule which destroy a specific antigen
(b) W.B.Cs. which eats bacteria
(c) Secretion of mammalian R.B.Cs.
(d) Component of Nucleus.
Answer:
(a) A molecule which destroy a specific antigen

Question 7.
One of the form of allergy is :
(a) Asthama
(b) Yellow eyes
(c) Typhoid
(d) Mumps.
Answer:
(a) Asthama

Question 8.
AIDS virus enters in human by :
(a) Food
(b) Kiss
(c) Water
(d) Blood.
Answer:
(d) Blood.

Question 9.
Credit of vaccine goes to :
(a) Alexander Fleming
(b) Edward Jenner
(c) Louis Pasteur
(d) Robert Koch.
Answer:
(b) Edward Jenner

Question 10.
Blood cancer is:
(a) Carcinoma
(b) Sarcoma
(c) Lymphoma
(d) Leukemia.
Answer:
(d) Leukemia.

Question 11.
AIDS test is known by :
(a) ELISA
(b) Australian antigen
(c) HIV test
(d) None of these.
Answer:
(a) ELISA

Question 12.
Reason of liver cancer is:
(a) Alcohol
(b) Tobacco
(c) Both (a) and (b)
(d) None of these.
Answer:
(a) Alcohol

Question 13.
Probe is used in:
(a) Fingerprinting
(b) Segregation of gene
(c) Identification of disease
(d) All of these.
Answer:
(d) All of these.

Question 14.
Monoclonal antibodies are used in :
(a) Identification of blood group
(b) Identification of pathogen
(c) Identification of cancer
(d) All of these.
Answer:
(d) All of these.

Question 15.
Study of embryological abnormalities are called :
(a) Tricology
(b) Terentology
(c) Traumatology
(d) Termitology.
Answer:
(b) Terentology

Question 16.
The disease occurs in embryonic stage of a child due to the use of the
Thalidomide by women:
(a) Vaginal carcinoma
(b) Microcephaly
(c) Phocomelia
(d) Viralism.
Answer:
(c) Phocomelia

Question 17.
A chemical substance that causes loss of sensation is called:
(a) Antianxiety
(b) Analgesic
(c) Anesthetic
(d) Exciting (Stimulating substance).
Answer:
(c) Anesthetic

Question 18.
In which part is opium found in plant:
(a) From leaves
(b) From fruits
(c) From seeds
(d) From bark.
Answer:
(b) From fruits

Question 19.
Lethal Hallucinogen is:
(a) Opium
(b) Morphine
(c) L.S.D.
(d) Heroin.
Answer:
(c) L.S.D.

Question 20.
Stimulant found in tea:
(a) Tannin
(b) Cocain
(c) Caffeine
(d) Freak.
Answer:
(c) Caffeine

Question 21.
Which of the following is narcotic opiate:
(a) Barbiturates
(b) Morphine
(c) Amphetamine
(d) L.S.D.
Answer:
(b) Morphine

Question 22.
Name the medicine which changes our mind:
(a) Psychotropic
(b) Hallucinogen
(c) Barbiturates
(d) Stimulants.
Answer:
(a) Psychotropic

2. Fill in the Blanks:

1. ………………….. prescribed the germ theory of disease.
2. ………………….. is the first human insulin which is made by genetic engineering.
3. AIDS is ………………….. transmitted disease.
4. Gonorrhoea is caused by …………………..
5. ………………….. genes which is responsible for cancer.
6. Blood cancer is known as …………………..
7. Hepatitis disease is caused by …………………..
8. Standard vaccine should not be …………………..
9. Pathogens are in living condition in …………………..
10. Cholera disease is caused by bacteria …………………..
11. ………………….. is a good technique to kill pathogens.
12. World Red Cross Day is celebrated on …………………..
13. The mixture of narcotic drugs is called …………………..
14. Benzodiazepine is ………………….. drug.
15. World Mental Health Day is celebrated on …………………..
16. L.S.D drug is obtained from ………………………… fungus.
17. The medicine which releases stress and edginess without sleeping is called …………………..

Answer:

1. Robert Koch
2. Humulin
3. Sexually
4. Neisseria gonorrhoeae
5. Oncogenes
6. Leukemia
7. Virus
8. Diseased and Poisonous
9. In living vaccine
10. Vibrio cholerae
11. Vaccination
12. 8th May
13. Cocktail
14. Psychotropic
15. 10th December
16. Claviceps purpurea
17. Tranquilizer.

3. Match the Following:
I.

Answer:

1. (e)
2. (f)
3. (d)
4. (a)
5. (b)
6. (c)

II.

Answer:

1. (d)
2. (a)
3. (e)
4. (b)
5. (c).

III.

Answer:

1. (d)
2. (e)
3. (a)
4. (b)
5. (c).

IV.

Answer:

1. (c)
2. (a)
3. (d)
4. (b)

4. Answer in One Word/Sentence :

1. Who has proposed germ theory of disease?
2. Name the vector of malarial parasite.
3. Name the genetically engineered human insulin.
4. Give full name of HIV.
5. Name the vaccines used for the vaccination of diphtheria, polio and whooping cough.
6. What is the source of opium?
7. Give two examples of stimulants.
8. Give the names of harmful chemical compounds of tobacco.
9. Give the name of source of LSD.
10. Give one example of sedative drugs.
11. Give one example of tranquilizer.
12. Name the drugs responsible for altering mood of man.

Answer:

1. Robert Koch
2. Plasmodium
3. Humulin
4. Human Immunodeficiency Virus
5. DPT vaccine
6. Papaver officinarum
7. Caffeine, cocaine
8. Nicotin
9. Claviceps purpurea (Fungus)
10. Benzodiazepines
11. Phenothiazines
12. Barbiturates.

Human Health and Disease Very Short Answer Type Questions

Question 1.
Name the carrier of malaria parasite.
Answer:
Female Anophelies mosquito.

Question 2.
Name 2 noninfectious diseases which are the major cause of mortality?
Answer:
Hepatitis-B, AIDS.

Question 3.
Name the vaccine which prevent Diphtheria, Polio and Tetanus.
Answer:
DPT and Polio vaccine.

Question 4.
Define diseases.
Answer:
The disease is a condition when the functions of one or more organs/systems of the body are adversely affected by various symptoms.

Question 5.
Which disease is cured by chemotherapy?
Answer:
Cancer.

Question 6.
Name 2 protozoan disease.
Answer:
Amoebiasis, malaria, Kalaazar

Question 7.
Give three examples of stimulating substances.
Answer:
Caffeine, cocaine, amiphimine.

Question 8.
Give the scientific name of the malarial parasite.
Answer:
Malarial parasite – Protozoan – Plasmodium falciparum

Question 9.
Write the source of LSD.
Answer:
Claviceps purpurea.

Question 10.
Give one example of tranquilizers.
Answer:
Phenothiazine.

Question 11.
What is the name of a drug which converts thoughts and feelings of human and causes fear?
Answer:
Psychedelic drugs.

Question 12.
Name the vector responsible for chikungunya. (Delhi 2008)
Answer:
Aedes mosquito.

Question 13.
Name the method which is used in the diagnosis of AIDS.
Answer:
ELISA Test.

Question 14.
In different parts of the country, Chikungunya is clarified. Name the carrier of this disease.
Answer:
Chikungunya is spread through bites from A. aegypti mosquitoes.

Question 15.
Name the types of Immunity.
Answer:
Immunity is two types:

1. Innate immunity,
2. Acquired immunity.

Question 16.
Write the full name of the pathogen that causes AIDS? (CBSE 1996)
Answer:
Human immunodeficiency virus – HIV

Question 17.
Name the types of tumours.
Answer:
Tumours are of two types :

1. Benign and
2. Malignant.

Question 18.
What is AIDS (HS&B 98)
Answer:
Acquired Immuno Deficiency Syndrome.

Question 19.
When the inability to open the mouth because human chewing areca nuts in betel quid or its variants (gutkha) and jaw muscles become hard. Give the name of the possible disease.
Answer:
Submucous fibrosis disease.

Question 20.
Name the full form of DPT.
Answer:
Diphtheria, Pertussis, and Tetanus.

Question 21.
What is the side effects of cancer treatment?
Answer:
Hair falling and Anemia.

Question 22.
Name the disease in humans where the myelin sheath of nerve cells is attacked by antibodies of itself. (CBSE 2005)
Answer:
Multiple sclerosis.

Question 23.
Which plant extract is called marijuana?
Answer:
Cannabis sativa.

Question 24.
Why is antibody-mediated immunity called humoral immunity?
Answer:
Antibodies are the glycol proteins that circulate in the body fluids (humor) hence it is called humoral immunity.

Question 25.
What is the second name of Mary Mallon?
Answer:
The second name of Mary Mallon is Typhoid Mary.

Question 26.
How does colostrum provide initial protection against diseases to newborn infants? Give reason.
Answer:
Colostrum contains antibodies like IgA, which provide initial protection against diseases.

Question 27.
Which body organs are affected by Pneumonia?
Answer:
Lungs and Alveolies are affected.

Question 28.
What is the confirmation test of Typhoid?
Answer:
Typhoid fever can be confirmed by the Widal test.

Question 29.
Write the full form of LSD.
Answer:
Lysergic Acid Diethylamide.

Question 30.
What is MALT?
Answer:
MALT refers to the lymphoid tissue located with in the lining of the major tracts (respiratory, digestive, urogenital tract)

Question 31.
Name the two major groups of cells required in attaining specific-immunity.
Answer:
B-cells and T-cells.

Question 32.
Why does an AIDS patient suffer from many other infectious disease?
Answer:
Due to the reduction in a number of helper T-cells, the immune system becomes weak. Consequently, the patient suffers from infectious disease.

Human Health and Disease Short Answer Type Questions

Question 1.
Define the following:
(a) Immunity
(b) Vaccine
(c) Interferon
(d) Vaccination.
Answer:
(a) Immunity: The capacity of an organism to fight with the disease and causal organisms is known as Immunity. The Immunity is due to B and T cells.
(b) Vaccine: The chemical substances which protect our body from disease-causing organisms are called vaccines.
(c) Interferon: Interferon is an antiviral protein which is produced within animal cells due to stimulus produced after viral infection and which prevents the infection and multiplication of other viruses.
(d) Vaccination: Vaccination is the process by which resistance against a specific disease is created in any living organism.

Question 2.
Distinguish between Inborn and Acquired immunity.
Answer:
Differences between Inborn and Acquired immunity are :

Question 3.
What is auto-immunity?
Answer:
This is an abnormality which sometimes develops in the immune system of the body. Instead of destroying foreign molecules, it starts attacking the body’s own cells leading to serious consequences. Such diseases are called autoimmune diseases.

Auto-immune diseases depend on the type of self-antigen involved. If the self-antigens are R.B.Cs. then the body destroys its own R.B.Cs. resulting in chronic anaemia. When the self-antigen is a muscle cell, it results in the destruction of its own-muscles resulting in severe weakness, when the self-antigens are liver cells, it results in chronic hepatitis.

Question 4.
Write the scientific names of two helminthiasis that are pathogene to man. Name the disease caused by them.
Answer:

• Ascaris lubricoides causes Ascariasis
• Wuchereria bancroffi causes filariasis or elephantiasis.

Question 5.
What is B-cells and T-cells? Explain it
Answer:
B-lymphocytes or B-cells produce an army of protein called antibodies in blood. In response to pathogens, T-lymphocytes or T-cells help B-cells to produce antibodies immune response are produced by these two types of lymphocytes.

Question 6.
Which types of diseases are protected by D.P.T. vaccine? Write the name of pathogens for each disease.
Answer:
D.P.T. vaccine is protect three types of disease :

(i) Diphtheria
(ii) Pertussis
(iii) Tetanus.
Name of the Pathogens:

Question 7.
What is Eugenics?
Answer:
Eugenics: The branch of biology which deals with the study of improvements of human race is called eugenics.
Importance:
1. Development of selective reproduction in similar species.
2. Transfer of genetic materials in various organisms.
3. Development of GM food and GM crops.
4. Gene cloning.
5. Gene therapy, etc.

Question 8.
Name and explain the type of barrier of the innate immune system, which involves.
Answer:
Cellular barrier
This barrier involves certain types of

• Polymorphs nuclear leucocytes
• Monocytes
• Natural killed cells
• Macrophages.

Question 9.
What is Drug addiction? What are its causes?
Answer:
Addiction is most common problem of our youths because they start to take different types of drugs and alcoholic beverages due to various reasons. It makes them habitual and dependent on them. Addiction is the habitual, psychological and physiological dependence on a substance or practice which is beyond voluntary control. A person who is habituated to a substance or a practice especially harmful one, is called drug addiction.
Its causes are :

• Curiosity
• Fun and stimulation
• Will of doing more work
• Feeling of freeding
• Temporary escape from life problems.

Question 10.
Write down the differences between Sedative and Tranquilizer.
Answer:
Differences between Sedative and Tranquilizer:

 

Question 11.
Give the name of source of LSD. Give its effects also.
Answer:
LSD (Lysergic Acid Diethylamide): It is a crystalline amidated alkaloid which is obtained from the sclerotium of ergot fungus Claviceps purpurea, pathogen of ergot disease of rye.
LSD causes horrible dreams, hallucinations, chronic psychosis and damage the brain. LSD was tried as treatment for alcoholism, neurosis and cancer patients. LSD brings about chromosomal and foetal abnormalities. Pathological condition caused by LSD abuse or by eating grain affected by ergot is called ergotism.

Question 12.
Describe the cell mediate immunity.
Answer:
Cell mediate immune response is effected by T-lymphocyte. These are two types of T- lymphocytes.

• Cytotoxic or killer T- cells, which kill the antigens in a variety of mechanisms.
• Helper T-cells slimulate the B-lymphocyte to produce antibodies. This immunity is responsible for rejection of transplants.

Question 13.
Write withdrawal symptoms of addiction.
Answer:
Withdrawal symptoms from Addiction: When a drug-dependent person fails to get the drug, he feels severe physical and psychological disturbances. These are called withdrawal symptoms. It includes tremors, nausea, vomiting, weakness, insomnia, anxiety run fits, decreased appetite, restlessness, elevated blood pressure, rapid heartbeat and epilepsy. These symptoms indicates that the body of addict person is unable to further use of intoxicant and they should stop it immediately.

Question 14.
Explain metastasis. Why is it fatal?
Answer:
The rapid growth of cancerous tumour causes overcrowding and disruption of normal cells. It extends to neighbouring tissues. In the last stage, bits of tumour tissue breakoff and are carried by the circulating blood or lymphs to other parts of the body, where they invade new tissues and start new tumors called secondary tumors. This property is called metastasis. It is fated due to increasing interference with the body’s life processes.

Question 15.
What are sedative? What are its types? Write its effect.
Answer:Sedative : Drugs which directly depress the brain and central nervous system are included in this group. They make the body free from anxiety and lethargic. The excessive use leads to sleep. Sleep causing drugs are also called Hypnotics.
It is of two types :

1. Barbiturates and
2. Benzodiazepines.

1.  Barbiturates: It is a sedative and tranquilizer. It suppresses brain’s activity and creates a feeling of relaxation, drowsiness and sleepiness.
2. Benzodiazepines: These drugs are commonly prescribed to help relieve anxiety in people who have anxiety disorder or another mental illness where anxiety is a symptom. They are very addictive.

Question 16.
What are lymph nodes? What is their function in our immune system?
Answer:
Lymph nodes are small solid structures located at different points along the lymphatic system. They serve to tray the microbes and other antigens. These antigens trapped in the lymph nodes are responsible for the activation of lymphocytes to cause the immune system.

Human Health and Disease Long Answer Type Questions

Question 1.
What is cancer? Write the names of two types of cancer and causes of cancer.
Answer:
Cancer: When tumours are formed due to the unorganized and uncontrolled division of cells, then it is called cancer.
Types of Cancer: Cancer is not a single disease but a complex of many diseases. Today about 200 distinct types of cancer have been recognized.

These are grouped into four main types:

1. Carcinomas
2. Sarcomas
3. Lymphomas and
4. Leukemias.

1. Carcinomas: The tumours which are made up of epithelial cells of ectodermal or endodermal origin are called carcinomas, e.g., solid tumours in nerve tissues and in tissues of body surfaces or their attached glands. It includes breast, skin, cervical and brain carcinomas.

2. Sarcomas: Hie tumours which are made up of connective tissue cells of mesodermal origin are called sarcomas. e.g., solid tumours growing from connective tissues, bones, cartilages and muscles. It constitutes only about 2% of human cancers.

3. Lymphomas: Cancers in which there is excessive production of lymphocytes by the lymph nodes and spleen are called lymphomas, e.g., Hodgkin’s disease. It constitute about 5 % of human cancers.

4. Leukemias: It is cancer of blood characterized by excessive number of W.B.Cs. (or leucocytes) in the blood (neoplastic growth). These cells invade into bone-marrow, lymph nodes and the spleen. It is more frequent in the children of age group 5 to 7 years but it can occur at any age. Acute leukemia causes death. It has no sure remedy. It constitutes about 4% of human cancers.

Causes of Cancer: Physical and chemical factors which cause cancer are called carcinogens. The main causes of cancer are as follows:

• Smoking causes mouth and lung cancer.
• Radiation, such as X-rays, ultraviolet rays and other ionizing radiations causes cancer.
• Viruses may cause cancer.
• Chemical substances such as Nicotine, caffeine, products of combustion of coal and oil, polycyclic hydrocarbons may cause cancer.

Symptoms of Cancer: There are some symptoms of cancer which must be kept in mind:

• Any lump or thickening in the tissue especially in breast, tongue or lip.
• A wound that is not healing.
• Any sudden change in mole or warts.
• Persistent indigestion and difficulty in swallowing things.
• Regular cough and hoarseness in sound.
• Unusual weight loss.
• A change in bowel habits.
• Any ulcer that does not get well.
• Bleeding in the vagina at times other than menstruation.
• Non-injury bleeding from the surface of the skin, mouth, or any other opening of the body.

Question 2.
Justify the following statements
(i) Smoking leads to a deficiency of oxygen in the body tissue.
(ii) Cancer patients are administered – interferon
(iii) Chewing of tobacco causes an increase in blood pressure.
Answer:
(i) Smoking increases the carbon monoxide (CO) content in blood and reduces the concentration of haem-bound oxygen hence there is deficiency of oxygen in the body tissues.

(ii) Tumor cells avoid detection and destruction by our immune system. Interferon-like biological modifiers activate the immune system and help in destroying the tumor cells.

(iii) By chewing tobacco the nicotine reaches the blood and stimulates the adrenal glands to release adrenaline and noradrenaline, both these hormones increases the blood pressure.

Question 3.
What is immune system? Describe various components of immune system of man and its role.
Answer:
The Immune system or Immunity (A Specific Defence Mechanism) : The ability of an organism to resist the pathogen or development of disease resistance is known as immunity and the study of immunity is called immunology, while the infected person with no disease is called immune. The most peculiar characteristic of immune system is that it can differentiate the self (body’s own cells) and non-self (foreign microbes).

Cells of the Immune System : Lymphocytes are the type of W.B.Cs. or Leucocytes which are chief cells of immune system of body. There are two types of lymphocytes that promote cellular immunity and humoral immunity. Both of these types of lymphocytes are derived from lymphocyte stem cells in the bone-marrow in the embryo.

1. T-cells of lymphocytes : These cells eventually migrate to the lymphoid tissue. Before doing so, the lymphocytes first migrate to thymus gland and are processed in the gland, hence called T-lymphocytes or T-cells. These are responsible for cellular immunity. There are following types of T-cells :

Killer T-cells : Killer T-cells or KT-cells directly attack and destroy antigen. In doing so, they move to the site of invasion and produce some chemical that attracts and stimulate phagocytes to feed more voraciously on antigen.
Helper T-cells : Helper T-cells or HT-cells stimulate B-cells to produce more antibody.
Suppressor T-cells: Suppressor T-cells or ST-cells keep entire immune system to attack on the own body cell.

Mode of action of T-cells to antigens : T-cells are antigen specific (each T-cell recognizes a specific antigen and different types of T-cells are stimulated by different types v of antigens). When a T-cell is stimulated by specific antigen, T-lymphocytes divide ripidly to form a clone of T-cells called lymphoblasts. T-cells live for 4-5 years or even longer. T- cells of a clone are morphologically similar but they perform different functions. According to their functions, their are three classes of T-cells, i.e., killer T-cells, helper T-cells and 1 suppressor T-cells.

2. B-cells of lymphocytes: The other population of lymphocytes which produces antibodies are processed in some unknown area, possibly liver or spleen. This population ‘ was firstly discovered in birds in which processing occurs in the bursa of fabricus, a structure not found in mammals. For this reason they are called as B-cells or B-lymphocytes. They are responsible for humoral immunity.

Mode of action B-cells to antigens: Once a B-cells is activated by the antigen, it multiplies very fast and forms a clone of plasma cells. Most of these produce antibody at a tremendous rate of 2,000 molecules per second. These antibodies circulate in the lymph to fight the antigen. So, forming humoral immune system. B-cells are short lived and are replaced by new cells from the bone-marrow after every few days.
The capacity of B-cells to produce specific antibodies is acquired during its development and maturation.

Question 4.
Describe the harmful effects of tobacco smoking.
Answer:
Effect of chewing and smoking Tobacco: The chewing and smoking of tobacco affects us in the following ways :

• It affects the route of the transfer of nerve impulse and central nervous system. In low concentration nicotine stimulates the conduction of nerve impulse but long-term use reduces the activity of nervous system.
• Nicotine stimulates the release of adrenaline leading to high blood pressure. Increased blood pressure due to smoking enhances the risk of heart diseases.
• It retards foetal growth in pregnant women.
• The smoke of tobacco contains aromatic hydrocarbons and tar along with carbon monoxide (CO). Carbon monoxide reduces the oxygen-carrying capacity of the blood. Hydrocarbons induces cancer. Due to these reasons tobacco chewing person suffer from mouth cancer and smokers suffer from throat and lung cancers.
• The use of tobacco in any form stimulates the secretion of saliva and gastric juices due to which acidity is increased in stomach. It may cause ulcers in the wall of stomach. The absorption capacity of mucous membrane of stomach also decreases. Thus, a person get suffered from hyponutrition, loss of appetite and constipation.
• Smoking also affects the activity of kidneys.
• Nicotin relaxes the muscular and skeletal tissues due to which person becomes weak.
• Long-term smoking may also cause diseases like bronchitis and Emphysema.
• Smoking reduces immunity of the body.
• Lips of smokers may become dark coloured. Teeth and fingers get stained. The breath becomes foul.

Question 5.
What are the causes of addiction?
Answer:
Causes of addiction are : Young peoples take drugs and alcoholic beverages and other intoxicans substances because of the following reasons:

• Curiosity: It is one of the most important cause of addiction because curiosity is generated among young peoples due to the advertisement of drugs in newspapers and other means of communication. So, that they take them for fust time and then became habitual.
• Fun and Stimulation: Some drugs are stimulative in nature. These drugs are used to increase body power but regular use of these drugs make them habitual. These drugs cause physical and mental weakness.
• Will of doing more work: It is believed that the use of intoxicating substances increases die capacity of the body and person is able to do more physical and mental work. But it is not true because these substances increases mental and physical fatigues.
• Feeling of freedom.
• Inability to face problems of life.
• Encouragement or Pressure by friends.
• Temporary escape from life problems.
• Mental relaxation.
• Relax from pain.
• Feeling of freedom, etc.

Question 6.
Explain the different methods of detecting cancer.
Answer:
Cancer can be detected by

• Biopsy and histopathological studies of the tissue
• Using antibodies against cancer-specific antigens
• Blood and bone marrow test to check the count of WBC and RBC
• Use of C T scans (Computerised tomography) MRI (magnetic resonance imaging) and X-rays to detect the cancer of internal parts.
• Applying principles of molecular biology to detect the genes in individuals with inherited susceptibility to cancer.

MP Board Class 12th Biology Solutions

MP Board Class 12th General English Unseen Passages

Comprehension’ शब्द

‘Comprehend’ से बना है। ‘Comprehend’ का अर्थ ‘समझना’ होता है। Comprehension Test का अभिप्राय विद्यार्थी को अंग्रेजी के दिए हुए passage के अर्थ को समझने की योग्यता की परीक्षा लेना है। अत: अंग्रेजी का कोई अपठित passage देकर कुछ प्रश्न पूछे जाते हैं जिनके उत्तर उस passage में से ही देने होते हैं। Passage के अर्थ को समझ लेने पर प्रश्नों के उत्तर देना कठिन नहीं होता है। अतएव passage को ध्यानपूर्वक पढ़कर ही उत्तर देना चाहिए।

सभी उत्तरों का विद्यार्थी के अपने शब्दों में होना आवश्यक नहीं है।
“Students can obtain the answer to (several of the) questions by copying the relevant part or parts of the text.”

इस प्रश्न को ऐसे हल करें :

1. Express yourself in a clear and coherent manner. Your language should be simple and correct, while your expression need be forceful.
   अपने विचारों को सुस्पष्ट एवं सुसम्बद्ध विधि से प्रकट करो। तुम्हारी भाषा सरल और सही हो, जबकि अभिव्यक्ति प्रभावशाली।
2. Use small and simple sentences.
   छोटे तथा साधारण वाक्यों का प्रयोग करो।
3. You can state your answer in more than one sentence as long as you keep to the point.
   तुम जब तक अपने सन्दर्भ की सीमा में रहो, अपने उत्तर को एक से अधिक वाक्यों में लिख सकते हो।
4. The answer should be neither too long nor too short.
   उत्तर न तो ज्यादा लम्बा होना चाहिए न ज्यादा छोटा।
5. Do not add any new ideas of your own unless you are asked to do so.
   जब तक निर्देशित न किया जाय तब तक कोई नया मत या विचार अपनी तरफ से मत जोड़ो।
6. Read the passage carefully two or three times.
   गद्यांश को दो या तीन बार पढ़ो।
7. Try to grasp the general sense of the passage.
   गद्यांश का सामान्य अर्थ ग्रहण करने की कोशिश करो।

Solved Examples

Read the following passages carefully and answer the questions given below them:

1. The Jataka Stories recount the many previous births of the Buddha in human and animal lives. In all there are 547 stories, originally told by the Buddha to his disciples. They were written down in Pali Language around 400 B.C. and absorbed into the Buddhist Canon not long ago after his death. The stories show the progression of his lives through many incarnations, gradually acquiring the wisdom, selflessness and thoughtfulness which eventually lead to enlightment. In each birth he performed some meritorious deed to bring him spiritual progress. Here is one of his stories.

A hare once lived in the forest with his animal friends, the jackal, the otter and the monkey. The animal respected the hare as he was wise and gentle. One day he said that they should all fast and give whatever food they gathered to whoever needed it. So the monkey found ripe mangoes, the jackal found a Lizard and a pot of milk and the otter found a fish. But the hare could not find any food and vowed that if anyone is hungry, he would offer him his own body. His tremendous vow was heard by the earth herself, who told Sakka, Lord of the devas. He decided to test the hare.

Sakka entered the forest disguised as a beggar and asked hare for food. Please eat my body’ the hare replied without hesitation.

So Sakka built fire and the hare willingly ran into the flames. Feeling no pain, he rose up to heaven. In gratitude, Sakka drew an image of hare on the moon for everyone to see and remember the hare’s selfless sacrifice. [2016]

Questions:
(A) Jataka stories are related to the previous incarnations of
(i) Lord Krishna (ii) Mahaveer (iii) Dattatraya (iv) Gautam Buddha.

(B) The stories are written in Language.
(i) Sanskrit (ii) Pali (iii) Prakrit (iv) Awadhi.

(C) The wise animal was
(i) Monkey (ii) Otter (iii) Hare (iv) Jackal.

(D) Sakka entered the forest in disguise of
(i) a beggar (ii) a monk (iii) a fakir (iv) a peasant.

(E) The Jataka Stories contain stories. [1]
(i) 547 (if) 457 (iii) 754 (iv) 745.

(F) Word previous relates to [1]
(i) Present (ii) Past (iii) Future.

(G) Monkey found as food to be given to needy person. [1]
(i) Bananas (ii) Guavas (iii) Ripe mangoes (iv) Oranges.

(H) The Jataka stories were written in [1]
(i) 400 A.D. (ii) 400 B.C. (iii) 420 A.D. (iv) 420 B.C.

(I) What reward did Sakka give to hare for his self-sacrifice? [2]
(J) What do the Jataka Stories show? [2]
Answers:
(A) (iv)
(B) (ii)
(Q) (ii)
(D) (i)
(E) (i)
(F) (ii)
(G) (iii)
(H) (ii)

(I) Sakka drew an image of hare on the moon for everyone to see and remember the hare’s selfless sacrifice.
(J) The Jataka stories show the progression of Buddha’s lives through many incarnations gradually acquiring the wisdom, selflessness and thoughtfulness which eventually lead to enlightenment.

2. The “Pench National Park” [Mogliland] is one of famous National parks in the world. It is in between Nagpur and Jabalpur city. There is also the center point of India. It is on the road National Highway 07. We can reach Kanyakumari from Kashmir by this road. Park is also known as “Mogliland” because of the “Jungle boy”-“Mogli” named later. The history of Seoni district and gazette says about a “miracle” which is related with the Jungle boy and the herd of dangerous wild animals. The boy was^born at Chorgarthiya village now it is very near to the park in Seoni district, M.P. One day when the little innocent boy of [1]8 months was a sleeping out side of the hut, her mother left him and went to her fields. The herd of animals came there and lifted the innocent for their dinner. With the help of history and gazette of Seoni and friends to “Rudyard Kipling”, an Australian novel writer, wrote the famous “Jungle book” novel. Its main script based on Mogli’s true life.

Mogli the hero of the famous Jungle book grew up among .dangerous herd of animals. He ate, ran, jumped, made sounds and helped them with human skills. We have seen in a Television serial in 1989. History says he lived with animals round about 24 years. We know very well that human has great affection to several animals but it is “One and only “miracle” in the modem world” that “animal brought up a human”. Why they give time to grow up? Why did they not eat the boy? It is wonderful. So Pench National Park called the Mogliland because he passed his life and acted like animal in the area. MP’s Ex. Forest Minister, Lt. Harbansh Singh who was very devoted to the children of schools and education, worked a lot for Mogliland and started a program named ‘Mogli Utsav’ for school students of MP in [2002].

“Save animals life”. [2015]
Questions:
(A) Gazette means:
(i) a book (ii) question paper (iii) government documents (iv) paper for printing.

(B) Mogliland is situated between Nagpur and city.
(i) Indore (ii) Jabalpur (iii) Gwalior (iv) Bhopal.

(C) Write the verb form of the word ‘wonderful’:
(i) Wonder (ii) Wonderful (iii) Wander (iv) Wonderfully.

(D) Pench National Park is known as :
(i) Mogliland (ii) Landmark (iii) England (iv) Island.

(E) “Rudyard Kipling,” wrote a novel its name is :
(i) A history (ii) The Jungle book (iii) Paikbook (iv) Book of Australia.

(F) Who had lifted the innocent child Mogli?
(i) Tiger (ii) Dogs (iii) A herd of animals (iv) Fox.

(G) Select the correct alternative that is the opposite of the word ‘pet’
(i) tame (ii) wild (iii) loving (iv) homely.

(H) Who started Mogli Utsav? Who was forest Minister then?
(i) Harbans Singh (ii) Randheer Yadav (iii) Mr. V. Niranjan (iv) Deepak Saxena.

(J) Who is the hero of the famous novel ‘The Jungle Book’?
(K) Why is “The Pench National Park” called Mogliland?
Answers:
(A) (iii)
(B) (ii)
(Q (i)
(D) (i)
(E) (ii)
(F) (iii)
(G) (ii)
(H) (i)

(I) The hero of the famous novel ‘The Jungle Book’ is Mogli.
(J) The Pench National Park is called Mogliland because Mogli passed his life and acted like animal in that area.

3. How did man discover salt? We are not sure. Perhaps, the cattle of Stone Age tribesmen found and fed on* salt licks or salt rocks. Their masters may have carried pieces of the salt rock to their caves. Salt springs were found to provide a more constant supply of salt. Villages grew around these springs. Man cut down trees for fuel for evaporating water to obtain salt. In China, the early human settlements were near salt pans on the Yellow River. Everywhere in the world, salt production has been going on for thousands of years. The ancient Greeks and Romans included salt in the offerings they made to their gods. The preservative quality of salt made it a specially fitting symbol of enduring fidelity. The word salt was used in phrases conveying high esteem and honor, in ancient and modem languages. In English, the expression, “the salt of the earth”, describes a person greatly respected by the community.

It was considered a prestigious item of commerce and civilizations flourished because of it. The sea has always been man’s most important source of salt supply. When oceans recede, salt ponds and salt marshes are left behind.

The Romans were famous roadbuilders. One of their roads called the Salt Route, built around 400 B.C. exists even today. In those days, salt from Rome was carried along this road to central Italy. The early Egyptians were supplied with salt from swamps at the mouth of the Nile. [2014]

Questions:
(A) What is the meaning of ‘prestigious’? [1]
(i) having respect (ii) religious (iii) business (iv) necessary.

(B) The noun form of the word‘describe’ is : [1]
(i) describe (ii) description (iii) described (iv) redescribe.

(C) The opposite of the word ‘modem’ is : [1]
(i) new (ii) early (iii) ancient (iv) recent.

(D) The of the tribesmen may have carried salt to their caves. [1]
(i) servant (ii) master (iii) friend (iv) neighbour.

(E) The constant supply of salt was made by : [1]
(i) salt springs (ii) rivers (iii) forests ‘ (iv) early man.

(F) The early Egyptians used to get salt from swamps at the mouth of [1]
(i) Nile river (ii) sea (iii) Yellow river (iv) salt rocks.

(G) In those times, around the springs, grew. [1]
(i) cities (ii) villages (iii) roads (iv) forests.

(H) ‘The salt of the earth’ means : [1]
(i) a person greatly respected in the society (ii) the salt that we get from salt springs (iii) the salt offered to gods (iv) a person not respected in the society.

(I) Why do you think salt is very important since early days? Mention two points. [2]
(J) How was the ‘Salt Route’ important for the Romans? [2]
Answers :
(A) (i)
(B) (ii)
(C) (iii)
(D) (ii)
(E) (i)
(F) (i)
(G) (ii)
(H) (i)

(I) Salt is very important since early days because :
(i) the cattle of Stone Age tribesmen were fed on salt licks,
(ii) salt has preservative quality.

(J) The ‘salt route’ was important for the Romans because in those days salt from Rome was carried along this road to central Italy.

4. Garbage is a great environmental hazard. It comes from various sources used paper, tiffin packings, plastic bags, ice-cream wrappers, bottle caps, fallen leaves from trees and many more.

Garbage makes the premises ugly, unkempt and breeds diseases. A lot of trash that is thrown away contains material that can be recycled and
reused such as paper, metals and glass which can be sent to the nearest recycling centre or disposed of to the junk dealer. It also contains organic matter such as leaves which can enrich soil fertility. A compost pit can be made at a convenient location where the refuse can be placed with layers of soil and an occasional sprinkling ofVater. This would help decomposition to make valuable fertilizer. This would also prevent pollution that is usually caused by burning such organic waste. [2013]

Questions:
(A) The main sources of Garbage in present conditions : [1]
(i) Household things (ii) Plots and other materials (iii) Water and liquid (iv) Plastic bags.

(B) Leaves can enrich fertility. I
(i) water (ii) soil (iii) air (iv) human body.

(C) The noun form of the word ‘recycled’ : [1]
(i) recycle (ii) recycling (iii) recycling (iv) to recycled.

(D) Give the meaning of ‘nearest’ : [1]
(i) closest (ii) closely (iii) fir (iv) far away.

(E) Give a great environmental hazard : [1]
(i) water pollution (ii) air pollution (iii) garbage (iv) all of these.

(F) Garbage makes premises: [1]
(i) clean (ii) beautiful (iii) ugly (iv) dry.

(G) We can dispose garbage to a : [1]
(i) Grocer (ii) Vendor (iii) Bookseller (iv) Junk dealer.

(H) Garbages can be reused by [1]
(i) re-selling (ii) recycling (iii) repairing (iv) renovating.

(I) What are the sources of garbages?. [2]
(J) Mention two things which help organic waste material to change into fertilizer in the compost pit. [2]
Answers :
(A) (i)
(B) (ii)
(C) (ii)
(D) (i)
(E) (iv)
(F) (iii)
(G) (iv)
(H) (ii)

(I) The sources of garbage are used paper, tiffin packings, plastic bags, ice-cream wrappers, bottle caps, fallen leaves from trees etc.

(J) (i) Layers of Soil
(ii) Sprinkling of water.

5. Old people say that childhood is the best part of life. They look back at their childhood and remember all its happy days, the jolly games, the fun they had at school, the sweets land cakes they used to eat, jokes they used to play and endless discussions they had among friends about almost every topic. Perhaps these old folks are right. And yet they forget many things that were not so pleasant in their childhood. There is a funny story that tells of a boy, who was crying because he had to go back to school after the holidays and the father scolded him and said, “Why, I only wish i could be a boy and go to school again. And all in a moment the father was little boy and his son was a grown-up man like his father. And the father, in the shape of a little boy, had to go to school, and I can tell you he did not like it at all. A child’s troubles may seem small to grown-ups but they are very big to him. [2017]

Questions :
(A) What are the joys of childhood? [1]
(i) games, work hard and fun (ii) labor and work only (iii) eating cakes only (iv) games, fun eating sweets and cakes.

(B) Give the opposite of‘ forget’. [1]
(i) dark (ii) dull (iii) remember (iv) call.

(C) Would old people be happy, if they became children again? [1]
(i) Yes (ii) May be (iii) May not be (iv) No.

(D) What wish did the father make? [1]
(i) He had been a child again (ii) He would become an old-man (iii) He would become a young boy (iv) He would become a rich man.

(E) Givemeaningof‘little’. [1]
(F) Give Adjective form of (II and III form degree)—‘Good’. [1]

(G) Why was the boy crying? [1]
(i) He wanted a lollipop (ii) He did not want to go to school (iii) He had not done his home-work (iv) He was hurt.

(H) To whom does a child’s troubles seem big? [1]
(i) to a mother (ii) to a father (iii) to a child (iv) to a teacher.

(I) What were the things which were not pleasant in the childhood? [2]
(J) How does the author compare Childhood and old age? [2]
Answers :
(A) (iv)
(B) (iii)
(C) (iii)
(D) (i)
(E) Small.
(F) (II) form—Better (III) form—Best.
(G) (ii)
(H) (iii)

(I) Going back to school after holidays and getting scolding from parents were not pleasant in the childhood.
(J) To the author childhood is the best part of life as one looks back at life. It is so because people remember all the games, fun and lovely things but they forget many things that were not so pleasant.

6. Nationalism, of course is a curious phenomenon; which at a certain stage in a country’s history gives life, growth, strength and unity, but at the same time, it has tendency, to limit one, because one thinks of one’s own country as something different from the rest of the world. The perspective changes and one is continuously thinking of one’s own struggles and virtues and failure to the exclusion of other thoughts. The result is that the same nationalism, which is the symbol of growth for a people becomes a symbol of cessation of that growth in the mind. Nationalism, when it becomes successful, sometimes goes on spreading in an aggressive way and becomes a danger internationally. Whatever line of thought you follow, you arrive at the conclusion that some kind of balance must be found, otherwise, something that was good can turn into evil. Culture, which is essentially good, becomes not only static but aggressive and something that breeds conflict and hatred when looked at from a wrong point of view. How do you find a balance?, I do not know. Apart from political and economic problems of the age, perhaps [1] that is the greatest problem today; because behind it there is a tremendous conflict in the spirit of man and a tremendous search for something it cannot find. We turn to economic theories because they have undoubted importance.

It is folly to talk of culture or even of God when human beings starve and die. Before one can talk about anything else; One must provide the normal essentials of life to human beings. That is where economics comes in. Human beings today are not in the mood to tolerate this suffering and starvation and inequality when they see that the burden is not equally shared. Others gain profit while they only bear the burden. [2018]

Questions :
(A) Nationalism is a symbol of [1]
(i) pride (ii) humbleness (iii) growth (iv) culture.

(B) Culture is essentially good but becomes : [1]
(i) dynamic (ii) static (iii) worse (iv) rotten.

(C) We can find balance when we turn to : [1]
(i) economics (ii) history (iii) culture (iv) geography.

(D) The word ‘starve’ in the passage means : [1]
(i) to die of hunger (ii) poverty (iii) lack of strength (iv) diseases.

(E) According to Nehru; Nationalism is a …. phenomenon. [1]
(i) natural (ii) cultural (iii) curious (iv) ethical.

(F) What is the verb form of ‘conclusion’? [1]
(i) include (ii) conclude (iii) conclusive (iv) concludable.

(G) It is folly to talk of culture when : [1]
(i) human beings starve and die (ii) the burden is not equally shared (iii) culture becomes aggressive (iv) nationalism becomes successful

(H) The noun form of ‘tolerate’ is : [1]
(i) tolerance (ii) tolerable (iii) tolerably (iv) toleration.

(I) When does a society become static? [2]
(J) According to Nehru when is it folly to talk about culture or God? [2]
Answers :
(A) (iii)
(B) (ii)
(C) (i)
(D) (i)
(E) (iii)
(F) GO
(G) (i)
(H) (i)

(G) It is folly to talk of culture when :
(I) A society becomes static when it looks at culture from a wrong point of view.
(J) According to Nehru, it is folly to talk of culture or even God when human beings starve and die.

7. Man’s journey of life from childhood to old age is very charming and colorful. Youth is the most exciting period of man’s life, when it is time to grow and dream. A young man is frill of hope, energy and zeal. Nothing is difficult or impossible or dangerous for him. The old people say that youth is not daring but thoughtless. A young man bums the candle at both ends. He commits mistakes and learns only after burning his finger. Sometimes the young men misuse their freedom and thus invite difficulties by their foolish actions. They are full of strength, energy and enthusiasm. They become rebels and are no longer afraid of facing the forces of realities. A young man accepts the challenge of evil, difficulties and hardships, to win or lose the game of life is the mission of his career. He loves to lead an adventurous life and has a keen desire to build up a new world of his dream. But the period of youth does not last long. Soon it is followed by old age, when he regrets his past mistakes and failures. The weak old man feels helpless, depressed and disappointed. He becomes unfit for any adventure. But some fortunate old people never grow old and continue to feel young and active and make the most of even the last years of their lives. It will not be wrong to say that youth brings honour and old age commands respect.

Questions :
(A) Man’s journey of life from childhood to….is very charming and colorful. [1]
(i) Young age (ii) Old age (iii) Death

(B) Who is full of hope, energy and zeal? t
(i) A child (ii) An old man (iii) A young man.

(C) Who misuse their freedom? I
(i) Young men (iii) Women. (ii) Old men

(D) Youth is followed by : [1]
(i) Old age (ii) Death (iii) Neither of the above.

(E) Old age commands : [1]
(i) Admiration (iii) Halted. (ii) Respect

Find out words from the passage which mean :
(F) attractive. i

(G) goal. [1]
(H) dejected. [1]
(I) What is charming and colorful? [2]
(J) What is the most exciting period of man’s life? [2]
Answers :
(A) (i)
(B) (iii)
(C) (i)
(D) (i)
(E) (ii)
(F) charming
(G) mission
(H) depressed
(I) Man’s journey of life from childhood to old age is charming and colorful.
(J) Youth is the most exciting period of a man’s life.

8. Character is one of the greatest power in the world. In its noblest embodiment, it exemplifies human nature in its highest forms, for it exhibits man at his best.

Men of genuine excellence in very station of life-men of industry, of integrity, of high principle, of sterling honesty, of purpose command the spontaneous homage of mankind. It is natural to believe in such men, to have confidence in them, and to imitate them. All that is good in the world is upheld by them, and without their presence in it, the world would not be worth living in.

Although genius always commands admiration, character most secures respect. The former is more the product of brain power, the latter of heart power and in the long run it is the heart that rules in life.’ Men of genius stand to society in the relation of its intellect, as men of character of its conscience, and while the former are admired; the later are followed.

Great men are always exceptional men, and greatness itself is best comparative. Indeed, the range of most men in life is so limited that very few have the opportunity of being great. But each man can act his part honestly and honorably and to the best of his ability. He can use his gifts and not abuse them. He can strive to make the best of life. He can be true, just, honest and faithful, even in small things. In a word, he can do his duty in that sphere in which providence has placed him.

Questions :
(A) Which is one of the greatest powers in the world? [1]
(i) Conduct (ii) Character (iii) Neither of the above.

(B) Genius commands : [1]
(i) Admiration ’ (ii) Respect (iii) Criticism.

(C) What rules life in the long run? [1]
(i) Head (ii) Heart (iii) Body.

(D) Who are exceptional men? [1]
(i) Great men (ii) Brave men (iii) Rich men.

(E) Who are followed by others? [1]
(i) Men of conscience (ii) Men of character (iii) Men of strength.

(F) Give the opposite of the word ‘best’. [1]
(G) Give the noun form of the word ‘believe’. [1]
(H) Select the word from the passage which means ‘chance’. [1]
(I) What is the force of character? [2]
(J) What sort of men command the homage of mankind? [2]
Answers :
(A) (ii)
(B) (i)
(C) (i)
(D) (i)
(E) (ii)
(F) worst.
(G) belief.
(H) opportunity.

(I) Character is one of the greatest powers in the world. In its noblest embodiment, it exemplifies human nature in its highest forms, for it
exhibits man at his best.
(J) Man of genuine excellence in every sphere of life commands the homage of mankind.

MP Board Class 12th English Solutions

In this article, we will share MP Board Class 12th Biology Solutions Chapter 2 पुष्पी पादपों में लैंगिक प्रजनन Pdf, These solutions are solved subject experts from the latest edition books.

MP Board Class 12th Biology Solutions Chapter 2 पुष्पी पादपों में लैंगिक प्रजनन

पुष्पी पादपों में लैंगिक प्रजनन NCERT प्रश्नोत्तर

प्रश्न 1.
एक आवृत्तबीजी पुष्प के उन अंगों के नाम बताइए जहाँ नर एवं मादा युग्मकोद्भिद का विकास होता है।
उत्तर
ना युग्मकोद्भिद का विकास पुंकेसर के परागकोष में, परागकण (Pollengrain) के रूप में होता है तथा मादा युग्मकोद्भिद का विकास स्त्रीकेसर (Pistil) के अण्डाशय में बीजाण्ड के अन्दर होता है (भ्रूण कोष (embryo sac) के रूप में)।

प्रश्न 2.
लघुबीजाणुधानी तथा गुरुबीजाणुधानी के बीच अंतर स्पष्ट कीजिए। इन घटनाओं के दौरान किस प्रकार का कोशिका विभाजन सम्पन्न होता है ? इन दोनों घटनाओं के अंत में बनने वाली संरचनाओं के नाम बताइए।
उत्तर
लघुबीजाणुधानी तथा गुरुबीजाणुधानी में अंतर

प्रश्न 3.
निम्नलिखित शब्दावलियों को सही विकासीय क्रम में व्यवस्थित कीजिएपरागकण, बीजाणुजन ऊतक, लघुबीजाणु चतुष्क, परागमातृ कोशिका, नर युग्मक।
उत्तर
उपर्युक्त शब्दावलियों का विकासीय क्रमानुसार सही क्रम निम्न प्रकार से हैंबीजाणुजन ऊतक, परागमातृ कोशिका, लघुबीजाणु चतुष्क, परागकण, नर युग्मक।

प्रश्न 4.
एक प्रारूपी आवृतबीजी बीजाण्ड के भागों का विवरण दिखाते हुए एक स्पष्ट एवं साफसुथरा नामांकित चित्र बनाइए।
उत्तर
बीजाण्ड की संरचना (Structure of ovule)-बीजाण्ड, अण्डाशय की दीवार से एक डण्ठल अथवा वृन्त द्वारा जुड़ा रहता है। इसे बीजाण्डवृन्त (Funicle) कहते हैं। बीजाण्डवृन्त जिस स्थान पर बीजाण्ड के शरीर से जुड़ा रहता है वह स्थान नाभिका (Hilum) कहलाता है। बीजाण्ड का मुख्य भाग बीजाण्ड-काय (Nucellus) कहलाता है। यह भाग पतली भित्ति वाली कोशिकाओं से निर्मित होता है। बीजाण्ड एक द्विस्तरीय अध्यावरण (Integuments) से ढंका रहता है, लेकिन कुछ बीजाण्डों में केवल एक ही अध्यावरण होता है। अध्यावरण बीजाण्डकाय को पूर्णतः नहीं ढंकते, बल्कि कुछ भाग खुला ही रह जाता है।

इस स्थान को बीजाण्डद्वार (Micropyle) कहते हैं। बीजाण्डकाय का आधारीय भाग निभाग (Chalaza) कहलाता है, यहीं से अध्यावरण पैदा होते हैं। बीजाण्डद्वार (Female gametophyte) के रूप में भ्रूणपोष (Embryo sac) पाया जाता है। भ्रूणपोष के अण्डद्वारी छोर की ओर तीन केन्द्रक मिलते हैं, इनमें से एक अण्ड-गोल (Egg of oosphere) व दो सहायक कोशिकाएँ (Synergids) बनाती हैं। निभागी छोर पर भ्रूणकोष में तीन प्रतिमुखी कोशिकाएँ (Antipodals) और बीचों- बीच द्वितीयक केन्द्रक (Secondary nucleus) पाया जाता है।

प्रश्न 5.
आप मादा युग्मकोद्भिद के एकबीजाणुज (Monosporic) विकास से क्या समझते हैं ?
उत्तर
बीजाण्ड में जब गुरुबीजाणु जनन की क्रिया होती है अर्थात् जब गुरुबीजाणु मातृ कोशिका का अर्द्धसूत्री विभाजन होता है तो उसमें चार गुरुबीजाणु मातृ कोशिकाएँ बनती हैं, इनमें से ऊपर की तीन गुरुबीजाणु कोशिकाएँ नष्ट हो जाती हैं तथा शेष एक सबसे नीचे का गुरुबीजाणु कार्यशील रहता है। यही कार्यशील गुरुबीजाणु मादा युग्मकोद्भिद (भ्रूणकोष) का विकास करता है। इस प्रकार एक अकेले गुरुबीजाणु से भ्रूणकोष . बनने की विधि को एकबीजाणुज विकास (Monosporic development) कहते हैं।

प्रश्न 6.
एक स्पष्ट एवं साफ-सुथरे चित्र के द्वारा परिपक्व मादा युग्मकोद्भिद् के 7-कोशीय, 8न्युक्लियेट (केंद्रक) प्रकृति की व्याख्या कीजिए।
उत्तर
एक प्ररूपी आवृत्तबीजी भ्रूणकोश परिपक्व होने पर 8-न्युक्लिकृत वस्तुतः 7-कोशिकीय होता है।

प्रश्न 7.
उन्मील परागणी पुष्पों से क्या तात्पर्य है ? क्या अनुन्मील्य परागणी पुष्पों में पर-परागण सम्पन्न होता है ? अपने उत्तर की तर्क सहित व्याख्या कीजिए।
उत्तर
उन्मील परागणी पुष्प (Chasmogamous flower) सामान्य पुष्पों की तरह हैं जिनमें परागकोष व वर्तिकान अनावृत्त अर्थात् खुले हुए होते हैं। अनुन्मील्य परागणी पुष्प (Cleistogamous flower) कभी न खिलने वाले पुष्प हैं । चूँकि ये पुष्प हमेशा ही बंद रहते हैं । अतः परागकोष व वर्तिकाग्र अनावृत्त नहीं हो पाते हैं। स्पष्ट है, इनमें पर-परागण सम्पन्न नहीं हो सकता, क्योंकि पर-परागण में किसी एक पुष्प के परागकोषों से निकले परागकणों का उसी प्रजाति के किसी दूसरे पौधे पर स्थित पुष्प के वर्तिकान पर स्थानान्तरण आवश्यक होता है। वास्तव में अनुन्मील्यता (Cleistogamy) स्व-परागण सुनिश्चित करने की एक युक्ति है।

प्रश्न 8.
पुष्पों द्वारा स्व-परागण रोकने के लिए विकसित की गई दो कार्यनीति का विवरण दीजिए।
उत्तर
पुष्पीय पादपों ने बहुत सारे ऐसे साधन के उपाय विकसित कर लिए हैं जो स्व-परागण को हतोत्साहित एवं पर-परागण को प्रोत्साहित करते हैं। स्व-परागण को रोकने के लिए एक अन्य साधन है, एकलिंगीय पुष्पों का उत्पादन। अगर एक ही पौधे पर नर तथा मादा दोनों ही पुष्प उपलब्ध हो जैसे-एरंड, मक्का, यह स्व-परागण को रोकता है। स्व-परागण रोकने का एक उपाय है स्व-असामंजस्य। यह एक वंशानुगत प्रक्रम है। उसी पुष्प या उसी पादप के अन्य पुष्प से जहाँ बीजांड के निषेचन को पराग अंकुरण या स्त्रीकेसर में परागनलिका वृद्धि को रोका जाता है।

प्रश्न 9.
स्व-अयोग्यता क्या है ? स्व-अयोग्यता वाली प्रजातियों में स्व-परागण प्रक्रिया बीज की रचना तक क्यों नहीं पहुँच पाती है ?
उत्तर
परागण बिल्कुल सही प्रकार के परागकणों का स्थानांतरण सुनिश्चित नहीं कराता है। प्रायः गलत प्रकार के पराग भी उसी वर्तिकान पर आ पड़ते हैं। स्त्रीकेसर में यह सक्षमता होती है कि वह पराग को पहचान सके कि वह उसी वर्ग के सही प्रकार का पराग (सुयोग्य) है या फिर गलत प्रकार का (अयोग्य) है। यदि पराग सही प्रकार का होता है, स्त्रीकेसर उसे स्वीकार कर लेता है तथा परागण-पश्च घटना के लिए प्रोत्साहित करता है जो कि निषेचन की ओर बढ़ता है। यदि पराग गलत प्रकार का होता है तो स्त्रीकेसर वर्तिकाग्र पर पराग अंकुरण या वर्तिका में पराग नलिका वृद्धि रोककर पराग को अस्वीकार कर देता है। एक स्त्रीकेसर द्वारा पराग के पहचानने की सक्षमता उसकी स्वीकृति या अस्वीकृति द्वारा अनुपालित होती है, जो परागकणों एवं स्त्रीकेसर के बीच निरंतर संवाद का परिणाम है।

प्रश्न 10.
बैगिंग (बोरावस्त्रावरण) या थैली लगाना तकनीक क्या है ? पादप जनन कार्यक्रम में यह कैसे उपयोगी है ?
उत्तर
यह पादप प्रजनन कार्यक्रम की एक प्रमुख विधि है । बैगिंग की प्रक्रिया में मादा जनक के रूप में लिए गए पुष्प को विपुंसन (Emasculation) के बाद बटर पेपर से बनी एक थैली द्वारा बाँध दिया जाता है। यह थैली ग्राह्य वर्तिकाग्र को किसी अवांछित परागकण से परागित नहीं होने देती। वर्तिकान को वांछित परागकण से परागित करने के बाद थैली पुनः बाँध दी जाती है ताकि अन्य कोई परागकण यहाँ न पहुँच सके। बैगिंग चयनित पादप प्रजनन कार्यक्रम की सफलता हेतु आवश्यक है ताकि केवल वांछित संकरण उत्पाद प्राप्त हो सके।

प्रश्न 11.
त्रि-संलयन क्या है ? यह कहाँ और कैसे संपन्न होता है ? त्रि-संलगन में सम्मिलित न्युक्लिआई का नाम बताइए।
उत्तर
एक सहायक कोशिका में प्रवेश करने के पश्चात् पराग नलिका द्वारा सहाय कोशिका के जीवद्रव्य में दो नर युग्मक अवमुक्त किए जाते हैं। इनमें से एक नर युग्मक अण्ड कोशिका की ओर गति करता है और केन्द्रक के साथ संगलित होता है, जिससे युग्मक संलयन पूर्ण होता है।

जिसके परिणाम में एक द्विगुणित कोशिका युग्मनज (जाइगोट) की रचना होती है। दूसरी ओर वह संगलित होकर त्रिगुणित (प्राइमरी इंडोस्पर्म न्युक्लियस (PEN)) प्राथमिक भ्रूणपोष केंद्रक बनाता है। जैसा कि इसके अन्तर्गत तीन अगुणितक न्युक्ली (केंद्रिकी) सम्मिलित होते हैं । अतः इसे त्रिसंलयन कहते हैं।

प्रश्न 12.
एक निषेचित बीजांड में, युग्मनज प्रसुप्ति के बारे में आप क्या सोचते हैं ?
उत्तर
भ्रूण भ्रूणकोष या पुटी के बीजांडद्वारी सिरे पर विकसित होता है। जहाँ पर युग्मन्ज स्थित होता है। अधिकतर युग्मनज तब विभाजित होते हैं जब कुछ निश्चित सीमा तक भ्रूणपोष विकसित हो जाता है। यह एक प्रकार का अनुकूलन है ताकि विकासशील भ्रूण को सुनिश्चित पोषण प्राप्त हो सके।

प्रश्न 13.
इनमें विभेद कीजिए
(1) बीजपत्राधार और बीजपत्रोपरिक
(2) प्रांकुर चोल तथा मूलांकुर चोल
(3) अध्यावरण व बीज चोल
(4) परिभ्रूण पोष एवं फल भित्ति।
उत्तर
(1) बीजपत्राधार एवं बीजपत्रोपरिक (Hypocotyl and Epicotyl)-
बीजपत्राधार व बीजपत्रोपरिक भ्रूणीय अक्ष के भाग हैं । भ्रूणीय अक्ष का बीजपत्र से जुड़ाव से नीचे का भाग बीज पत्राधार कहलाता है व इसके नीचे के भाग में मूलांकुर स्थित होता है। दूसरी ओर भ्रूणीय अक्ष का बीजपत्र से जुड़ाव से ऊपर का हिस्सा बीजपत्रोपरिक कहलाता है जिसके ऊपर प्रांकुर स्थित होता है।

(2) प्रांकुर चोल व मूलांकुर चोल (Coleoptile and coleorhia)-
एकबीजपत्री पौधों के बीज में प्रांकुर मूलांकुर सुरक्षात्मक आच्छद (Protective sheath) से ढंके रहते हैं। जैसा कि नाम से स्पष्ट है प्रांकुर का यह आच्छद प्रांकुर चोल तथा मूलांकुर का आच्छद मूलांकुर चोल कहलाता है।

(3) अध्यावरण व बीज चोल (Integument and Testa)-
बीजाण्ड के चारों ओर पाये जाने वाले एक या दो सुरक्षात्मक आवरण अध्यावरण कहलाते हैं । निषेचन के बाद जब बीजाण्ड परिपक्व होकर बीज के रूप में परिवर्तित होता है तब यह अध्यावरण बीज चोल कहलाता है।

(4) परिभ्रूणपोष व फलभित्ति (Perisperm and pericarp)-
बीजाण्डकाय (Nucellus) का वह भाग जो बीज बनने के बाद भी भ्रूणपोष के चारों ओर एक पतली परत के रूप में बचा रहता है परिभ्रूणपोष (Perisperm) कहलाता है। स्पष्ट है यह कुछ बीजों में ही पाया जाने वाला भाग है। दूसरी ओर निषेचन के बाद अण्डाशय त्रिस्तरीय फल भित्ति (Pericarp) में बदल जाता है। अत: पेरीकार्प फल से संबंधित है जबकि परिभ्रूणपोष बीज से। परिभ्रूणपोष एकस्तरीय तथा फलभित्ति प्रायः त्रिस्तरीय होती है।

प्रश्न 14.
एक सेब को आभासी फल क्यों कहते हैं ? पुष्प का कौन-सा भाग फल की रचना करता है?
उत्तर
कुछ प्रजातियों में जैसे-सेब, स्ट्राबेरी (रसभरी), अखरोट आदि में फल की रचना में पुष्पासन भी महत्वपूर्ण भागीदारी निभाता है। इस प्रकार के फलों को आभासी फल कहते हैं। अधिकतर फल केवल अण्डाशय से विकसित होते हैं और उन्हें यथार्थ या वास्तविक फल कहते हैं।

प्रश्न 15.
विपुंसन से क्या तात्पर्य है ? एक पादप प्रजनक कब और क्यों इस तकनीक का प्रयोग करता है?
उत्तर
यदि कोई मादा जनक द्विलिंगी पुष्प धारण करता है तो पराग के प्रस्फुटन से पहले पुष्प कलिका से परागकोश के निष्कासन हेतु एक जोड़ा चिमटी का प्रयोग आवश्यक होता है। इस चरण को विपुंसन कहा जाता है। विपुंसित पुष्पों को उपयुक्त आकार की थैली से आवृत्त किया जाना चाहिए जो सामान्यत: बटर पेपर की बनी होती है। ताकि इसके वर्तिकान को अवांछित परागों से बचाया जा सके। इस प्रक्रम को बैगिंग कहते हैं। यह तकनीक बढ़ियाँ किस्म के पादप प्राप्त करने के लिए व्यापक रूप से व्यापारिक पादप पुष्प उत्पादन करने वाले लोगों द्वारा अपनाई जा रही है।

प्रश्न 16.
यदि कोई व्यक्ति वृद्धिकारकों का प्रयोग करते हुए अनिषेकजनन को प्रेरित करता है तो आप प्रेरित अनिषेकजनन के लिए कौन-सा फल चुनते और क्यों?
उत्तर
यद्यपि अधिकतर प्रजातियों में फल निषेचन का परिणाम होते हैं, लेकिन कुछ ऐसी प्रजातियाँ भी हैं जिनमें बिना निषेचन के फल विकसित होते हैं। ऐसे फलों को अनिषेकजनित फल कहते हैं। इसका एक उदाहरण केला है। अनिषेक फलन को वृद्धि हार्मोन्स के प्रयोग से प्रेरित किया जा सकता है और इस प्रकार के फल बीजरहित होते हैं इसके अन्य उदाहरण हैं-बीजरहित अंगूर, संतरा, नीबू और टमाटर आदि। इस प्रक्रम द्वारा इन फलों तथा सब्जियों का सफलतापूर्वक व्यापारिक स्तर पर उत्पादन किया जा रहा है।

प्रश्न 17.
परागकण भित्ति रचना में टेपीटम की भूमिका की व्याख्या कीजिए।
उत्तर
परागकण भित्ति रचना की सबसे आंतरिक परत टेपीटम होती है। यह विकासशील परागकणों को पोषण देती है। टेपीटम की कोशिकाएँ सघन जीवद्रव्य (साइटोप्लाज्म) से भरी होती हैं और सामान्यतः एक से अधिक केन्द्रकों से युक्त होती है।

प्रश्न 18.
असंगजनन क्या है और इसका क्या महत्व हैं ?
उत्तर
कुछ पुष्पीय पादपों जैसे कि एस्ट्रेर्सिया तथा घासों ने बिना निषेचन के ही बीज पैदा करने की प्रक्रिया विकसित कर ली, जिसे असंगजनन कहते हैं। यदि संकर किस्म के संग्रहीत बीज को बुआई करके प्राप्त किया गया है तो उसकी पादप संतति पृथक्कृत होगी और वह संकर बीज की विशिष्टता को यथावत नहीं रख पाएगा। यदि एक संकर (बीज) असंगजनन से तैयार की जाती है तो संकर संतति में कोई पृथक्करण की विशिष्टताएँ नहीं होगी। इसके बाद किसान प्रतिवर्ष फसल-दर-फसल संकर बीजों का उपयोग जारी रख सकते हैं और उसे प्रतिवर्ष संकर बीजों को खरीदने की जरुरत नहीं पड़ेगी। संकर बीज उद्योग में असंगजनन की महत्ता के कारण दुनिया भर में, विभिन्न प्रयोगशालाओं में असंगजनन की आनुवंशिकता को समझने के लिए शोध और संकर किस्मों में असंगजनित जीन्स को स्थानांतरित करने पर अध्ययन चल रहे हैं। बागवानी एवं कृषि विज्ञान में असंगजनन के बहुत सारे लाभ हैं।

पुष्पी पादपों में लैंगिक प्रजनन अन्य महत्वपूर्ण प्रश्नोत्तर

पुष्पी पादपों में लैंगिक प्रजनन वस्तुनिष्ठ प्रश्न

1. सही विकल्प चुनकर लिखिए

प्रश्न 1.
निषेचन क्रिया है
(a) एक नर युग्मक का अण्डाणु से संयोजन
(b) परागकणों का परागकोष से वर्तिकाग्र पर स्थानान्तरण
(c) नर युग्मकों का ध्रुवीय केन्द्रकों से संयोजन
(d) बीजाण्ड से बीज का निर्माण।
उत्तर
(a) एक नर युग्मक का अण्डाणु से संयोजन

प्रश्न 2.
आवृत्तबीजियों में मादा युग्मकोद्भिद होता है
(a) गुरुबीजाणु मातृ कोशिका
(b) बीजाण्ड
(c) भ्रूणकोष
(d) बीजाण्डकाय।
उत्तर
(c) भ्रूणकोष

प्रश्न 3.
जीनिया शब्द प्रदर्शित करता है, पराग के प्रभाव को
(a) कायिक ऊतक पर
(b) जड़ पर
(c) पुष्प पर
(d) भ्रूणपोष पर।
उत्तर
(d) भ्रूणपोष पर।

प्रश्न 4.
यदि पुष्पीय पादप में गुणसूत्रों की द्विगुणित संख्या 12 होती है तब 6 गुणसूत्र उपस्थित होंगे
(a) बीजपत्री कोशिकाओं में
(b) भ्रूणपोष कोशिकाओं में
(c) सहायक कोशिकाओं में
(d) पर्ण कोशिकाओं में।
उत्तर
(c) सहायक कोशिकाओं में

प्रश्न 5.
निषेचन के पश्चात् बीजों के बीजावरण विकसित होते हैं
(a) अध्यावरणों से
(b) भ्रूणकोष से
(c) भ्रूणकोष के परिधीय भाग से
(d) ह्रासित सहायक कोशाओं से।
उत्तर
(a) अध्यावरणों से

प्रश्न 6.
पेरीस्पर्म होता है
(a) अपभ्रष्ट (हासित)द्वितीयक केन्द्रक
(b) अपमिश्रण
(c) अनिषेक फलन
(d) अनिषेक जनन।
उत्तर
(b) अपमिश्रण

प्रश्न 7.
जब बीजाण्डों के बिना निषेचन के अण्डाशय से फल विकसित होता है तो इस क्रिया को कहते
(a) अनिषेक बीजाणुभवन
(b) अपमिश्रण
(c) अनिषेक फलन
(d) अनिषेक जनन।
उत्तर
(c) अनिषेक फलन

प्रश्न 8.
बिना युग्मक के संयोजन के बीजाणदभिद का परिवर्धन कहलाता है
(a) अपमिश्रण
(b) अपबीजाणुता
(c) अपयुग्मकता
(d) परागण
उत्तर
(c) अपयुग्मकता

प्रश्न 9.
एक बीजाण्ड में अर्द्धसूत्री विभाजन होता है
(a) बीजाण्डकाय में
(b) गुरुबीजाणु मातृ कोशिका में
(c) गुरुबीजाणु में
(d) आर्कीस्पोरियम में।
उत्तर
(b) गुरुबीजाणु मातृ कोशिका में

प्रश्न 10.
पुष्पी पादपों में नर युग्मक पाय जाते हैं
(a) परागकण में
(b) पुंकेसर में
(c) बीजाण्ड में
(d) उपर्युक्त सभी में।
उत्तर
(a) परागकण में

प्रश्न 11.
परागनली का कार्य है
(a) परागण में सहायता
(b) वर्तिकाग्र की सुरक्षा
(c) नर युग्मक वाहक
(d) उपर्युक्त सभी।
उत्तर
(c) नर युग्मक वाहक

प्रश्न 12.
निभाग पाया जाता है
(a) भ्रूणकोष में
(b) बीजाण्ड में
(c) परागनली में
(d) उपर्युक्त सभी में।
उत्तर
(b) बीजाण्ड में

प्रश्न 13.
एकबीजपत्री में बीजपत्र स्थित होता है
(a) शीर्षस्थ
(b) पार्वीय
(c) आधारीय
(d) किसी भी स्थिति में।
उत्तर
(b) पार्वीय

प्रश्न 14.
सूरजमुखी में पाया जाता है-
(a) स्वपरागण
(b) परपरागण
(c) उपर्युक्त सभी
(d) उपर्युक्त में से कोई नहीं।
उत्तर
(c) उपर्युक्त सभी

प्रश्न 15.
भ्रूणपोषी केन्द्रक होता है
(a) अगुणित
(b) द्विगुणित
(c) त्रिगुणित
(d) उपर्युक्त में से कोई नहीं।
उत्तर
(b) द्विगुणित

प्रश्न 16.
द्विनिषेचन प्रक्रिया (त्रिगुण संयोजन) की खोज की थी
(a) नवास्चिन ने
(b) ल्यूवेनहॉक ने
(c) स्ट्रॉसबर्गर ने
(d) हॉफमिस्टर ने।
उत्तर
(a) नवास्चिन ने

प्रश्न 17.
वह परागण जिसमें आनुवंशिक रूप से भिन्न परागकण व वर्तिकान परस्पर मिलते हैं, कहलाता (AMU 2012)
(a) सजातपुष्पी परागण
(b) अनुन्मील्य परागण
(c) परनिषेचन
(d) उन्मीलनिमील परागण।
उत्तर
(c) परनिषेचन

प्रश्न 18.
यदि एक पौधे की जड़ की कोशिकाओं में गुणसूत्रों की संख्या 14 है तो उसकी सहायक कोशिकाओं में कितने गुणसूत्र होंगे ___ (BHU 2012)
(a) 14
(b) 21
(c) 7
(d) 28.
उत्तर
(c) 7

प्रश्न 19.
अपस्थानिक बहुभ्रूणता पायी जाती है (BHU 2012)
(a) पोआ में
(b) ब्रेसिका में
(c) एलियम में
(d) सिट्रस में।
उत्तर
(d) सिट्रस में।

प्रश्न 20.
स्पोरोपॉलिनिन किसके बहुलकीकरण से बनता है ___ (BHU 2012)
(a) वसा एवं फीनॉल के
(b) कैरोटिनॉइड एवं वसा के
(c) वसा एवं एस्टर के
(d) कैरोटिनॉइड एवं एस्टर के।
उत्तर
(a) वसा एवं फीनॉल के

2. रिक्त स्थानों की पूर्ति कीजिए

1. बीज में भ्रूणपोष का प्रमुख कार्य ……………….. का संग्रहण होता है।
2. पक्षियों द्वारा होने वाला परागण ………………. कहलाता है।
3. सेब ……………….. फल का उदाहरण है।
4. ऊतक जिसके ऊपर बीजाण्ड लगे होते हैं, उसे ……………….. कहते हैं।
5. सूरजमुखी में ………………. प्रकार के पुंकेसर पाये जाते हैं।
6. पौधों में ……………….. से फल का विकास होता है।
7. मक्का के एक बीजपत्र को ……………….. कहते हैं।
8. ……………… में चतुर्दी/ पुंकेसर पाये जाते हैं।
9. भ्रूणपोषी बीजों में ……………….. पतली होती है।
10. बीजाण्ड में ……………….. से बीजाण्डवृन्त जुड़ा होता है।
11. आवृत्तबीजी पौधों में पुंकेसर नर ……………….. है।
12. टाइफा में ……………….. परागण पाया जाता है।
13. साल्विया में ……………….. परागण होता है।
14. परागकण की बाह्य भित्ति ……………….. कहलाती है।
15. बीज रहित फल बनने की क्रिया को ……………….. कहते हैं।
उत्तर-

1. भोज्य पदार्थ
2. आर्निथोफिली
3. कूटफल
4. जरायु
5. सिनजिनेशिवस
6. अण्डाशय,
7. स्कुटेलम
8. सरसों
9. कोशाभित्ति
10. नाभिका
11. जननांग
12. संयुक्त
13. कीट
14. बाह्यचोल,
15. अनिषेकजनन।

3. सही जोड़ी बनाइए’


उत्तर
1.(e),2 (d), 3. (b), 4.(a), 5. (c).

4. एक शब्द में उत्तर दीजिए

1. पुष्प के चार चक्रों के नाम लिखिये।
2. ऐसे पौधे जो अपने जीवन में कई बार पुष्प उत्पन्न करते हैं उनके लिये किस शब्द का उपयोग किया जाता है ?
3. बीज के बाहरी आवरण का नाम लिखिये।
4. चमगादड़ के द्वारा परागित पुष्प का उदाहरण दीजिये।
5. जब बाहादल पुंज तथा दल में अन्तर नहीं होता है तो इसके लिये किस शब्द का उपयोग किया जाता है ?
6. चमगादड़ द्वारा संपन्न होने वाले परागण का नाम लिखिये।
7. निषेचन के बिना फल बनने की क्रिया क्या कहलाती है ?
8. अनिषेकजनन द्वारा किस प्रकार के फल बनते है ?
9. पैराशूट विधि द्वारा प्रकीर्णन का एक उदाहरण दीजिए।
उत्तर-

1. बाह्यदल, दल, पुंकेसर, स्त्रीकेसर,
2. बहुवर्षीय
3. बीजचोल
4. कदम्ब
5. दलाभ
6. चिरोप्टेरीफिली
7. अनिषेकफलन
8. बीजरहित
9. ट्राइडेक्स।

पुष्पी पादपों में लैंगिक प्रजनन अति लघु उत्तरीय प्रश्न

प्रश्न 1.
मादा युग्मकोद्भिद का विकास किस कोशिका में होता है ?
उत्तर
क्रियाशील गुरुबीजाणु मातृ कोशिका द्वारा।

प्रश्न 2.
मादा युग्मकोद्भिद का अन्य नाम बताइये।
उत्तर
भ्रूणकोष (Embryo sac)!

प्रश्न 3.
बीजाण्ड अपने लिए भोज्य पदार्थ किससे प्राप्त करता है ?
उत्तर
बीजाण्ड अपना भोज्य पदार्थ बीजाण्डासन से प्राप्त करता है।

प्रश्न 4.
अनुन्मील्य पुष्य किसे कहते हैं ? उदाहरण बताइये।
उत्तर
ऐसे द्विलिंगी पुष्प जो कभी नहीं खुलते हैं, वे अनुन्मील्य पुष्प कहलाते हैं, उदाहरण-कोमेलाइना।

प्रश्न 5.
परागकण के बाह्य चोल में पाये जाने वाले कठोर प्रतिरोधक कार्बनिक पदार्थ का नाम बताइये।
उत्तर
स्पोरोपोलेनिन (Sporopollenin)

प्रश्न 6.
वायु परागित पुष्पों के लक्षण बताइये।
उत्तर
प्रायः सफेद रंग, बहुत छोटे तथा परागकण अधिक संख्या में बनते हैं।

प्रश्न 7.
पुष्पीय पादपों में भ्रूणपोष की सूत्रगुणिता क्या होती है ?
उत्तर
त्रिगुणित।

प्रश्न 8.
किसी एक द्विबीजपत्री भ्रूणपोषी बीज का उदाहरण दीजिए।
उत्तर
अरण्ड (Ricinus)।

प्रश्न 9.
कूट या आभासी फलों के दो उदाहरण दीजिये।
उत्तर
सेब, कटहल।

प्रश्न 10.
उभयलिंगाश्रयी शब्द का अर्थ बताइये।
उत्तर
उभयलिंगाश्रयी (Monoecius) वे पौधे हैं जिन पर एकलिंगी नर व मादा पुष्प अलग-अलग लगे रहते हैं, जैसे-मक्का

पुष्पी पादपों में लैंगिक प्रजनन लघु उत्तरीय प्रश्न

प्रश्न 1.
अनिषेकजनन क्या है ? इसका क्या महत्व है ?
उत्तर
अनिषेकजनन (Parthenogenesis)-प्रजनन की वह विधि है जिसमें अण्ड (Ovum) या मादा युग्मक बिना निषेचन के भ्रूण तथा नये पादपों में विकसित हो जाता है। अध्ययन के दौरान यह देखा गया है कि अनिषेकजनन के लिए परागण का होना अनिवार्य है। यह एक उत्तेजना का कार्य करता है। यूलोथ्रिक्स, स्पाइरोगायरा तथा सोलेनेसी और कम्पोजिटी कुल की कुछ जातियों में इस विधि द्वारा प्रजनन होता है। ऐसा देखा गया है कि इस प्रजनन से बने पौधे सामान्यतः छोटे एवं बन्ध्य होते हैं। कभी-कभी कुछ पौधों में बगैर निषेचन के अण्डाशय सामान्य फल के रूप में विकसित हो जाता है। इस प्रकार से फल निर्माण को अनिषेकफलन (Parthenocarpy) कहते हैं। केला, सेब, अंगूर, नाशपाती, पपीता, अमरूद आदि में प्राकृतिक रूप से अनिषेकफलन पाया जाता है।

प्रश्न 2.
बहुभ्रूणता क्या है ?
उत्तर
बहुभ्रूणता (Polyembryony)-जब एक ही बीज में एक से अधिक भ्रूण पैदा हो जाते हैं तो इस प्रजनन या दशा को बहुभ्रूणता कहते हैं। बहुभ्रूणता नीबू जाति के पौधों में सामान्य रूप से पायी जाती है। कोनीफर्स की कई जातियों में भी यह पायी जाती है, क्योंकि इनके बीजाण्डों में कई स्त्रीधानियाँ पायी जाती हैं। निकोशियाना में बहुभ्रूणता भ्रूण की बाह्य त्वचा के मुकुलन के कारण पैदा होती है। इसके अलावा बहुभ्रूणता की स्थिति धान व गेहूँ में भी पायी जाती है। जब बीजाण्ड में एक से अधिक अण्ड या भ्रूणकोष तथा सभी अण्ड निषेचित हो जाएँ या जाइगोट विभाजित हो जाए तब बहुभ्रूणता की स्थिति पैदा होती है।

प्रश्न 3.
परागकोष की संरचना का सचित्र वर्णन कीजिए।
उत्तर
परागकोष की रचना (Structure of Anther)-परागकोष की अनुप्रस्थ काट को देखने में उसमें पालियाँ दिखाई देती हैं। प्रत्येक पालि में दो कोष्ठ होते हैं जिन्हें परागकोष (Pollensacs) कहते हैं। परागकोष की दोनों पालि योजी (Connective) से जुड़ी रहती हैं । परागकोष के भीतरी स्तर पर पोषक ऊतक होता है जिसे टैपीटम (Tapetum) कहते हैं ।

इनकी कोशिकाएँ वृद्धि करके परागकणों को भोजन प्रदान करती हैं जो अन्त में नष्ट हो जाती हैं। शुरुआत में परागकोष में असंख्य परागजनन कोशिकाएँ (Pollen mother cells) जन्म लेती हैं। ये परागजनन कोशाएँ अर्द्धसूत्री विभाजन द्वारा चार परागकण (Pollen grains) बनाती हैं । इस परागकण में गुणसूत्रों की संख्या आधी रहती है।

प्रश्न 4.
स्व-परागण के लिए आवश्यक चार परिस्थितियों का उल्लेख कीजिए।
उत्तर

1. द्विलैंगिकता (Bisexuality)-जब नर और मादा अंग एक ही पुष्प में उपस्थित रहते हैं तो स्व-परागण की सम्भावनाएँ अधिक बढ़ जाती हैं।
2. समकालपक्वता (Homogamy)-स्व-परागण के लिए यह भी आवश्यक है कि नर तथा मादा का परिपक्वन लगभग एक ही समय में हो, जैसे-पीली कटैली (Argemone) में।
3. सवन्त पुष्पता (Cleistogamy)-ऐसे पुष्प परिपक्वन के बाद भी नहीं खुलते, निमोलिक पुष्प कहलाते हैं। जैसे-मूंगफली (Groundnut) आदि में। इन पुष्पों में स्व-परागण अवश्य ही होता है।
4. पर-परागण की असफलता-कुछ पुष्पों में सामान्यतः पर-परागण ही होता है, परन्तु किसी कारण पर-परागण असफल हो जाये तो इनमें स्व-परागण होता है।

प्रश्न 5.
माइक्रोप्रोपेगेशन से आप क्या समझते हैं ?
उत्तर
माइक्रोप्रोपेगेशन (Micropropagation)-यह पादप प्रजनन की आधुनिक विधि है जिसमें मातृ पौधे के थोड़े से ऊतक से हजारों की संख्या में पादपों (Plants) को प्राप्त किया जा सकता है। यह विधि ऊतक तथा कोशिका संवर्धन तकनीक (Tissue and cell culture technique) पर आधारित है। इस विधि में ऊतक के एक छोटे से भाग को पौधे से (जिनका प्रवर्धन करना होता है) अलग कर लेते हैं और उसे पूतिहीन (Aseptic) दशाओं में पोषक माध्यम (Nutrient medium) पर वृद्धि कराते हैं । यह ऊतक विकसित होकर कोशिकाओं के एक गुच्छे के रूप में वृद्धि करता है इसे कैलस (Callus) कहते हैं । इस कैलस को काफी समय तक गुणन हेतु सुरक्षित रखा जा सकता है। इस कैलस का एक छोटा-सा भाग दूसरे पोषक माध्यम पर स्थानान्तरित कर दिया जाता है जहाँ पर यह छोटे पौधे या पादप के रूप में विभेदित होता है। इस पादप को निकालकर फिर मृदा में लगा देते हैं । इस विधि में कम समय में बहुत अधिक संख्या में मातृ पौधे के ऊतक से पादपों को प्राप्त किया जा सकता है। यह विधि आर्किड्स (Orchids), कार्नेशन्स (Carnations), गुलदाऊदी (Chrysanthemum) एवं एस्पैरेगस (Asparagus) में अधिक सफल हुई है।

प्रश्न 6.
निषेचन किसे कहते हैं ? निषेचन के दौरान परागनलिका का मार्ग नामांकित चित्र द्वारा दर्शाइए।
उत्तर
नर तथा मादा युग्मकों के संयुग्मन को Antipodal cells निषेचन (Fertilization) कहते हैं । यह जैव क्रिया लैंगिक जनन की मुख्य आधारशिला है। इस क्रिया में अगुणित युग्मक मिलकर युग्मनज (Zygote) बनाते हैं जो विकसित होकर पूर्ण जीव बनाता है।

प्रश्न 7.
स्व-परागण और पर-परागण में अंतर स्पष्ट कीजिए।
उत्तर
स्व-परागण और पर-परागण में अंतर– स्व-परागण (Self-pollination)

प्रश्न 8.
पर-परागण के कोई चार महत्वों को लिखिए।
अथवा पर-परागण के दो लाभ लिखिए।
उत्तर
पर-परागण के महत्व-

1. परपरागित पुष्पों की सन्ताने अधिक स्वस्थ तथा पुष्ट होती हैं।
2. पर-परागण द्वारा उत्पन्न सन्तानों में एक ही जाति के दो विभिन्न पौधों के गुणों का मिश्रण होता है। इनमें नये तथा उपयोगी गुणों के मिलने की संभावना हो जाती है ऐसे पौधे जीवन संघर्ष में अधिक सफल रहते हैं ।
3. पर-परागित पुष्पों के बीज अधिक समय तक जीवित रहने की क्षमता रखते हैं। इसके द्वारा पौधों की नयी-नयी जातियाँ तैयार की जाती हैं।
4. बीज अधिक संख्या में बनते हैं तथा फल सुन्दर तथा स्वादिष्ट होते हैं।

पुष्पी पादपों में लैंगिक प्रजनन दीर्घ उत्तरीय प्रश्न

प्रश्न 1. स्व-परागण क्या है ? स्व-परागण से होने वाले लाभ एवं हानियों का वर्णन कीजिए।
उत्तर
स्व-परागण (Self pollination)-जब एक ही पुष्प के परागण उसी पुष्प के या उसी पौधे के दूसरे पुष्प के वर्तिकाग्र पर स्थानान्तरित होते हैं तो उसे स्वयं परागण कहते हैं। इस परागण के होने के लिए यह अनिवार्य है कि, पौधा द्विलिंगी हो अर्थात् एक ही पौधे पर दोनों लिंगों के जनन अंग बनते हों।
स्व-परागण से लाभ-

1. परागकणों की अधिक मात्रा में आवश्यकता नहीं होती।
2. स्व-परागण की क्रिया सहज व सुलभ होती है।
3. स्व-परागण से बने बीज शुद्ध नस्ल वाले होते हैं ।
4. पुष्पों को रंग, सुगन्ध तथा मकरन्द स्राव करने की आवश्यकता नहीं पड़ती।
5. जिन पुष्पों में पर-परागण नहीं होता वहाँ पर स्व-परागण द्वारा निषेचन होता है।

स्व-परागण से हानियाँ-

1. स्व-परागित पुष्पों में बीज; संख्या में कम, हल्के व छोटे होते हैं।
2. परागण के बाद उत्पन्न पौधों में अच्छे व स्वस्थ पौधों के गुणों का सम्मिश्रण नहीं हो पाता ।
3. इस परागण से उत्पन्न पौधों में केवल एक ही पौधे के गुण होते हैं ।
4. इस परागण से उत्पन्न पौधे दुर्बल व अस्वस्थ होते हैं।
5. पादप विकास की सम्भावना घटती है।

प्रश्न 2.
द्विनिषेचन किसे कहते हैं ? महत्व लिखिए।
उत्तर
प्रायः सभी आवृत्तबीजीय पौधों में द्वि-निषेचन (Double-fertilization) क्रिया पायी जाती है। सर्वप्रथम इसकी खोज एस. जी. नवाश्चिन (1898) तथा ग्रिगनार्ड (1899) ने लिलियम तथा फ्रिटिलेरिया नामक पौधों में की थी। यह क्रिया संयुग्मन के पश्चात् होती है। भ्रूणकोष के अन्दर दो ध्रुव केन्द्रक आपस में संयुजन कर एक (2x) द्वितीयक केन्द्रक का निर्माण करते हैं। इस द्वितीयक केन्द्रक (2n) से एक नर केन्द्रक (n) संयुजन करता है, चूँकि दो बार संयुजन होता है, अतः इसे द्वि-निषेचन कहते हैं। द्वि-निषेचन के फलस्वरूप त्रिगुणित (3x) गुणसूत्रों वाला प्राथमिक भ्रूणपोष केन्द्रक बनता है और यह प्रक्रम त्रिःसंयोजन कहलाता है। भ्रूणपोष केन्द्रक से भ्रूणपोष बनता है। भ्रूणपोष बीज का मुख्य भोज्य पदार्थ संग्रह ऊतक होता है, जो भ्रूण के विकास तथा बीजों के अंकुरण के समय काम आता है।

महत्व-

1. इस क्रिया द्वारा बने बीज और पौधे स्वस्थ होते हैं।
2. भ्रूणपोष का निर्माण द्विनिषेचन से होता है, जिससे बढ़ते हुए भ्रूण को पोषण प्राप्त होता है।

प्रश्न 3.
भ्रूणपोष का विकास किस प्रकार होता है ?
उत्तर
भ्रूणपोष (Endosperm) बीज का मुख्य भोज्य-पदार्थ संग्रह ऊतक है। इसमें भोजन संगृहीत रहता है, जो भ्रूण के विकास एवं बीज के अंकुरण (Germination) के समय प्रयुक्त होता है । भ्रूणपोष के कारण भ्रूण का उचित परिवर्धन होता है तथा अच्छे स्वस्थ बीज बनते हैं।

विकास के आधार पर भ्रूणपोष निम्नलिखित तीन प्रकार के होते हैं –

1. केन्द्रकीय भ्रूणपोष (Nuclear endosperm) –
इस भ्रूणपोष के विकास में भ्रूणपोष केन्द्रक (Endosperm nucleus) बार-बार विभाजन कर स्वतन्त्र रूप से बहुत से केन्द्रक बनाता है जो परिधि पर विन्यसित हो जाते हैं। भ्रूणपोष के मध्य में एक केन्द्रीय रिक्तिका (Central vacuole) बन जाती है। यह रिक्तिका बाद में समाप्त हो जाती है और बहुत से केन्द्रक एवं कोशाद्रव्य इसमें भर जाते हैं । यह बाद में अनेक कोशाओं का निर्माण करते हैं। .

2. कोशीय भ्रूणपोष (Cellular endosperm)-
इस प्रकार के भ्रूणपोष निर्माण में भ्रूणपोष केन्द्रक के प्रत्येक विभाजन के पश्चात् कोशाभित्ति का निर्माण होता है।

3. हेलोबियल भ्रूणपोष (Helobial endosperm)-
यह केन्द्रकीय भ्रूणपोष एवं कोशीय भ्रूणपोष के बीच की अवस्था है। इसमें भ्रूणपोष केन्द्रक के प्रथम विभाजन के बाद कोशाभित्ति निर्मित होती है। बाद में इन दोनों भागों में केन्द्रक विभाजन होता रहता है और भित्ति निर्माण नहीं होता। भ्रूणपोष का विकास भ्रूणपोष केन्द्रक (Endosperm nucleus) से होता है। द्विनिषेचन के फलस्वरूप भ्रूणपोष केन्द्रक बनता है तथा त्रिगुणित (Triploid = 3n) होता है।

निम्नलिखित में अंतर स्पष्ट कीजिए

1. भ्रूणकोष तथा भ्रूणपोष
2. बीज तथा बीजाण्ड।
उत्तर
1. भ्रूणकोष तथा भ्रूणपोष में अन्तरभ्रूणकोष (Embryo sac)

2. बीज तथा बीजाण्ड।

प्रश्न 5.
नर युग्मक जनन क्या है ? पौधों में नर युग्मक जनन क्रिया का वर्णन कीजिए।
अथवा परागकणों के विकास का वर्णन कीजिए।
उत्तर
नर युग्मकजनन (Male gametogenesis)-नर युग्मकों के निर्माण को नर युग्मकजनन या लघुबीजाणुजनन कहते हैं। यह क्रिया पुंकेसर के परागकणों द्वारा होती है।परागकणों का विकास-प्रत्येक परागकोष (Anther) दो पालियों तथा प्रत्येक पालि दो-दो कोष्ठों की बनी होती है। प्रत्येक कोष्ठ की कोई एक कोशिका स्पष्ट तथा आकार में बढ़ जाती है जिसे मातृजन कोशिका (Sporogenous mother cell) कहते हैं ।

यह विभाजित होकर दो कोशिकाएँ बना देती हैं, अन्दर की ओर की कोशा को बीजाणुजनन कोशिका (Sporogenous cell) है तथा बाहरी को भित्तीय कोशिका (Parietal cell) कहते हैं। भित्तीय कोशिका बार-बार विभाजित होकर बीजाणुजनन कोशिका को घेरकर चारों तरफ दो या तीन स्तर बना देती हैं। बीजाणुजनन कोशिका भी विभाजित होकर एक समूह बना देती हैं जिनकी कोशिकाएँ पराग मातृ कोशिकाएँ (Pollen mother cells) कहलाती हैं। पराग मातृ कोशिकाओं के चारों ओर स्थित भित्तीय स्तर टैपीटम (Tapetum) कहलाती है और जो परागकणों को पोषण देती है।

यह स्तर बाद में नष्ट हो जाती है। अब पराग मातृकोशिका अर्द्धसूत्री विभाजन के द्वारा चार कोशिका बना देती हैं जो चतुष्टक (Tetrad) के रूप में स्थित होती है। प्रत्येक कोशिका के चारों तरफ बाह्यचोल तथा अन्तः चोल बन जाती है, अब इसे परागकण कहते हैं। . परिपक्व हो जाने के बाद परागकण, परागकोष में भर जाते हैं और स्फुटन के बाद बिखर जाते हैं तथा मादा जनन अंग के वर्तिकाग़ पर-परागण की क्रिया के द्वारा पहुँच जाते हैं।

MP Board Class 12th Biology Solutions

MP Board Class 12th General English Report Writing

अच्छी Report की विशेषताएँ :

1. Relevant [प्रासंगिक]-Report जिस घटना या गतिविधि को प्रस्तुत कर रही है, उससे सम्बन्धित सभी पहलुओं का सत्य एवं पूर्ण विवरण होना चाहिए। आँखों देखी या सुनी गई घटना या गतिविधि के अतिरिक्त [अन्य विषयों का] Report में समावेश नहीं होना चाहिए।
2. Brief [संक्षिप्त]-Report का संक्षिप्त होना अत्यावश्यक है। बहुत अधिक विस्तृत Report किसी भी दृष्टि से उपयोगी नहीं होती है।
3. Clear [स्पष्ट]-Report बिल्कुल स्पष्ट होनी चाहिए। किसी अस्पष्ट बिन्दु को इसमें सम्मिलित नहीं किया जाना चाहिए। रिपोर्ट की विषय-वस्तु व्यवस्थित होनी चाहिए।
4. Factual[वास्तविक]-Report तथ्यों पर आधारित होनी चाहिए। तथ्य प्रामाणिकता पर आधारित हों।
5. Report में अपनी राय नहीं देनी चाहिए।
6. Easy [सरल]-Report की भाषा सरल, स्पष्ट व शुद्ध हो।
7. Impressive [प्रभावशाली]-यह बहुत ही प्रभावशाली होनी चाहिए।
8. Report को प्रस्तुत करने से उसका पुनः अवलोकन करना चाहिए।

Some Examples

1. You are Kamal. As a responsible citizen, you have organized a campaign on ‘Say No to Polythene Bags’ in your locality. Write a report in not more than 125 words for publication in a magazine using the following details: [2018]

Campaign in our locality/disastrous effects of polythene/chokes the sewerage system/to make the public aware of its harms/to make locality polythene free zone.
Answer:

Say No to Polythene Bags

Gwalior, 10 October, 20……….. Anshul Raj. ‘Say No to Polythene Bags’ campaign has gained momentum all over the country and our city is no exception. It began with the efforts of a small NGO and today many individuals and organisations have joined the movement. 1 took the initiative to organise this campaign in our locality. Polythene bags have become popular on account of being cheap and convenient. The chief aim of this campaign was to make people aware of their ill effect. They make land infertile, choke the drains and take the life of stray animals if swallowed. They produce harmful gases on being burnt. It is not safe to carry or store eatables in polythene bags. An effort is being made to encourage people to use bags made out of cloth or paper. The campaign was a huge success. All the residents, shopowners and school children of our locality participated in the campaign. We had arranged for an audio-visual show to highlight the ill effects of polythene. Alll those present pledged to make our locality a ‘No polythene Zone’.

2. Using the following input, produce a write-up on ‘The Importance of English’ in about 150-200 words: [2015]

International Language, Invention of Internet, Language of Trade, Commerce higher technical and scientific studies communication round the globe, means for earning livelihood.
Answer:

Importance of English

English is an international language. It is spoken all over the world. It serves as an important link that connects people round the globe. It varies in vocabulary, accent and style nation to nation. This makes it one of the richest languages of the world. There are hundreds of additions to the vocabulary of English every year. So, it keeps on developing and growing. The invention of internet has revolutionised human life for much information is available for use at a click. Most of the material is in English through now it is being made available in other languages too. It is also the language of trade and commerce. Various trade documents, deals and agreements are drafted in English. It connects people engaged in national -and international business. The Higher Education in the field of Science, Technology, Medicine, Communication, Management, Law & Commerce is again imparted in the English medium. Thousands of students come to India and go to foreign countries to receive Higher Education in the various branches of learning. This again has become possible because of English. Thus, English has assumed great importance. The growing culture of convent education attests to this fact. English is the language used in offices, schools, colleges, courts, hospitals, media, corporate sector etc. It is the backbone of hotel and tourism industry. So, English is the means of livelihood.

3. Using the following input, produce a write-up on ‘My Neighbour’ in about 150-200 words: [2014]
His name, age, profession, His habits, nature, His qualities, Why you like him or dislike him.
Answer:

My Neighbour

My neighbour is Dr. Sunil Gupta. He is around forty years old and is an experienced and qualified doctor. He has a small and happy family comprising of his wife, a son, a daughter and his parents. He is very decent and well behaved. He is not only a good doctor but also a good neighbour. He never quarrels with anyone. He is very cooperative and sociable. He gives due respect to others. He is very fond of children and plays with them whenever he finds some time. He helps others readily. He never charges high fees from poor people and helps them with medicines. This is why he is liked by everyone in the locality. ,

4. Using the following input produce a write-up on ‘A Train Accident’: [2013]

A bus collides with a train, Location, Time, Date of accident, Casualties and Relief Dead and injured and reactions, Blood donors, Help of local people and high authorities.
Answer:

A Train Accident

Various accidents are reported everyday claiming the lives of many. A school bus collided with train at Alipur level crossing in Bhopal on March
20, 20 The students were returning from an excursion tour and it was almost dark. The crossing was not attended by any man. The bus was toppled over. The driver, conductor and two students died on the spot and eight others were seriously injured. The local inhabitants reported the matter to police and rushed the injured for medical help. The authorities took prompt action. Soon parents were informed. The local people generously donated blood and thus the life of many was saved.

5. You are Rohan residing at 12 Roop Rang Colony, Damoh, M.P. You have witnessed an accident. Write a report for a newspaper in 100 words about the accident using the following details:

1. Where, when and how did the accident happen?
2. People, vehicle involved, loss of life and property.
3. The scene of the accident, details of casualties-deaths, injured hospitalized.

Conclude with negligence of the commuters, suggestions to the government and people.
Answer:

A Road Accident

Damoh, 18 November, 20…. A number of accidents are reported on the roads of Damoh. A school van collided with the city bus claiming the lives of two adults and a child. The van driver tried to overtake the bus but collided with a bike. The bike toppled over and the van hit the outer wall of a nearby building. The mishap claimed the lives of the couple on bike and a school girl. Three other children were injured. They were taken to the nearby hospital. The commuters, however, only stopped to look at the scene but no one came forward to help the injured. The government should be strict about the number of children these vans be allowed to admit. A number of operators do not have a licence and also try to Overspeed. People and school authorities should also pay attention to wards it.

6. Last Sunday you went to the hospital to see a friend who was admitted there. Using the following input produce a small write-up on ‘A visit to a Hospital’ [2012]

Registration counter, people in front of doctors rooms, surgical ward, nurses attending, medicine ward, patients lying on their beds.
Answer:

A Visit to a Hospital

Last Sunday, I went to a hospital to see my friend who was admitted there due to some illness. At the entry gate, there was a registration counter. Patients had to register themselves before being allowed to consult the Doctors. The registration counter was full of patients. After the registration counter, there were doctors rooms on both sides of the verandah. O.P.D. patients where waiting for their number to come. The doctor’s rooms were followed by the surgical ward. This ward was full of patients. Here the patients were admitted after surgery. All kinds of patients after surgery were inside the ward. The nurses were attending the patients. Some of them were applying for medicines and bandaging the wounds of the patients.

They looked concerned towards the patients. The medicines ward was the last room. Here general patients were lying on their beds. The entire scene of the hospital was full of noise.

7. Using the following input produce a small write-up on ‘Polythene Bags’—A Great Nuisance’ :

Polythene bags most convenient and inexpensive soon became popular, proved extremely Harmful because non-degradable, dumped in fields, drains and gutters, choke drains and gutters hampering flow of sewage, stray animals eat them, get intestines choked and die.
Answer:

Polythene Bags—A Great Nuisance

Polythene bags are most convenient means to carry something. Since they are low in cost, the shopkeepers readily supply one when something is bought ranging from fruits, vegetables, groceries, sarees, suits etc. It has killed the habit of carrying shopping bags from home. Being convenient and cheap they have become very popular and affect the environment adversely. Their use has proved to be harmful on many accounts. Being non-degrad¬able they cannot be disposed and are thrown into fields, drains and gutters with the result that drains are choked and the flow of sewage is blocked. When burned they pollute the environment and release toxic gases affecting the health of all. Besides stray animals eat them and subsequently die. Therefore before the problem assumes alarming dimensions it is the right time, to say no to polythene bags.

8. With the help of the words given produce a write-up on the N.S.S. Camp : [2016]

1. N. S. S. Camp at Rampur Village,
2. 100 Volunteers,
3. Planting trees,
4. Cleaning of drains,
5. Adults literacy classes.

Answer:

N.S.S. Camp

The N.S.S. unit of H. S. School No, 2, Dhar, organised a camp at Rampur Village. The Camp lasted for ten days. Projects were stored out. Volunteers were divided into four groups. Tasks were assigned to them. First of all five hundred saplings were to be planted. Plants were distributed by the Horticulture Department of the district free of cost. The second phase of the campaign was to educate the villagers about protection of the environment. Streets and drains were cleaned. The villagers took part in the cleaning drive enthusiastically. The greatest accomplishment was the successful completion of our adult literacy campaign. Fifty adults were enrolled for adults literacy programme. ‘

9. With the help of the words given below produce a write-up on ‘The Value of Games’ : [2013, 16]

Necessary for life removes monotony, make our body healthy, learning good habits, develop equality and brotherhood.
Answer:

The Value of Games

Games and sports form an important part of human life. ‘All work and no play makes Jack a dull boy’ goes the saying. Just as studies are essential for our mental growth, games and sports are essential for physical growth. They keep the body fit and are a good means of entertainment. They develop team spirit and cooperation among players. Players are required to play as per the rules and this makes them disciplined. Thus, games develop sportsmanship, fair play and prepare them to face various challenges in life. Games like football, hockey, cricket etc., develop team spirit and proper coordination. Lastly, Games enable players to win laurels to their school, college, state and even country besides fame, money and respect.

10. An election was held and you went to cast your vote. Using the following inputs, describe in about 100 words, what you saw at the booth, as an observer :

Queue of voters/polling officers, presiding officer and polling agents/ indelible ink/polling box/electronic voting machine.
Answer:

A Scene at an Election Booth

In front of the polling booth, there was a long queue of people waiting for their turn to go in. Inside the booth, there were a couple of polling officers and a presiding officer on one side and some polling agents on the other. A polling officer was checking the voter’s name, marking it and demanding proof of identification. The other polling officer was putting an indelible ink mark on the voter’s index finger of the left hand. Then the presiding officer asked him to go into the voting box where he had readied the electronic voting machine for him to vote. The voter went in, pressed the button of his choice and left the booth.

11. Using the following input produce a write-up on ‘Illegal Immigration A Real Threat’: [2011]

2 crore illegal immigrants, social problems, altering demographic complexion, problem acute in some states and towns, burden on economic resources, security problem.
Answer:

Illegal Immigration—A Real Threat

Presently India is faced with the problem of illegal immigration. Illegal immigration refers to the entry of foreigners into Indian territory without obtaining necessary documents. According to an estimate, there are around two crore illegal immigrants in India. These immigrants are sources of social problems. They are fast assimilated into society and marry the natives. They acquire Indian citizenship and become part of Indian population. They have changed the demographic complexion of society. Thus, we have a wide range of socio-cultural groups propagating their culture, beliefs, ideas, etc. This problem is acute in Bengal, Bihar, A.P., U.P., Assam and almost all the North. Eastern states. These newly emerged states are an added burden on the economic resources-land, capital, food etc. India shares its borders with Pakistan, China, Bangladesh and the natives of these countries share some common features of culture, language, personality with the Indians Consequently, it becomes easy for the terrorists to take advantage of it and give practical shape to their destructive plans.

12. Write a report to be published in a newspaper giving a detailed account of inauguration ceremony of the annual function held in your school. Use the following details: [2014]

Name of the event, occasion, date, time, place, Chief guest, guest of honour and chairman of the function, welcome address, floral welcome, speeches by the guests, vote of thanks.
Answer:

Annual Day Celebrated

Gandhi Memorial Inter College; Bhopal celebrated its 15th Annual Day on March 23,20 The function was organized in the auditorium of school and began at around 4 pm in evening. The Honourable Education Minister of Madhya Pradesh was the Chief Guest. The Guest of Honour was Divisional Commissioner while the chairman of the function was the principal. The guests were received by the Principal and the staff. They were garlanded and intro¬duced by the Principal. The function started after the chief guest garlanded the altar of Goddess Saraswati and lighted a lamp in front of her. The Principal read out the annual report mentioning the various academic, cultural and sports activities held in the school. Meritorious students received prizes from the chief guest. The guests gave speech inspiring the students to work hard in life and aim for the best. The Principal thanked the guests for sparing their valu¬able time and presented momentos to them.

Exercises For Practice

1. Two students of your class, Mahesh and Navin quarrelled while you were looking on. The Principal has asked you to give him a factual report. Write it with the help of the following clues :
   Mahesh/walking fast/Navin’s desk/fell down/hurt knee/accused/other students intervened/stopped quarrelling.
2. Put the following information in the form of a report:
   School Canteen/no proper arrangement/of seats/a dirty cook/rude behaviour/sells rotten things/articles/waiter impolite/no cleanliness/ warned/complaints/no action taken.
3. Put the following information in the form of a report:
   A meeting/Science Club/organized/problems of science students/ discussed activities/conducted/plan prepared/next session/Principal/ appreciation.

MP Board Class 12th English Solutions

MP Board Class 12th Biology Solutions Chapter 4 जनन स्वास्थ्य

जनन स्वास्थ्य NCERT प्रश्नोत्तर

प्रश्न 1.
समाज में जनन स्वास्थ्य के महत्व के बारे में अपने विचार प्रकट कीजिए।
उत्तर
जनन स्वास्थ्य का तात्पर्य जनन के सभी पहलुओं जैसे शारीरिक, भावनात्मक, व्यावहारिक तथा सामाजिक स्वास्थ्य से है। दुनिया में भारत पहला ऐसा देश है जिसने राष्ट्रीय स्तर पर जननात्मक स्वस्थ समाज को प्राप्त करने की कार्य योजनाएँ बनाई हैं। इन कार्यक्रमों को परिवार कल्याण के नाम से जाना जाता है। इनकी शुरूआत 1951 में (परिवार नियोजन के नाम से) हुई थी। जनन संबंधित और आवधिक क्षेत्रों को इसमें सम्मिलित करते हुए बहुत उन्नत व व्यापक कार्यक्रम फिलहाल ‘जनन एवं बाल स्वास्थ्य सेवा कार्यक्रम (आ.सी.एच.)’ के नाम से प्रसिद्ध है। इन कार्यक्रमों के अंतर्गत् जनन संबंधी विभिन्न पहलुओं के बारे में लोगों में जागरूकता पैदा करते हुए और जननात्मक रूप से संबंध समाज तैयार करने के लिए अनेक सुविधाएँ एवं प्रोत्साहन दिए जा रहे हैं।

प्रश्न 2.
जनन स्वास्थ्य के उन पहलुओं को समझाइए, जिस पर आज के परिदृश्य में विशेष ध्यान देने की जरूरत है
उत्तर
जनन स्वास्थ्य प्राप्ति के लिए विभिन्न कार्य-योजनाओं के सफलतापूर्वक क्रियान्वयन के लिए मजबूत संरचनात्मक सुविधाओं, व्यावसायिक विशेषज्ञता तथा भरपूर भौतिक सहारों की आवश्यकता होती है। लोगों को जनन संबंधी समस्याओं जैसे-सगर्भता (Pregnancy), प्रसव (Parturition), यौन संचारित रोगों, गर्भपात (Abortion), गर्भ निरोधकों, आर्तव चक्र संबंधी समस्याओं, बांझपन (Infertility) आदि के बारे में चिकित्सकीय सहायता देने के लिए बेहतर तकनीकों एवं नई कार्य योजनाओं को क्रियान्वित करने की भी आवश्यकता है ताकि लोगों की अधिक सुचारु रूप से देखभाल और सहायता की जा सके।

बढ़ती “मादा भ्रूण हत्या” की कानूनी रोक के लिए ऐम्नियोसेंटेसिस (Amniocentesis) जैसे लिंग परीक्षण पर वैधानिक प्रतिबंध तथा व्यापक बाल प्रतिरक्षीकरण (टीकाकरण) आदि कुछ महत्वपूर्ण कार्यक्रमों को शामिल किया गया है। जनन संबंधी विभिन्न अनुसंधानों को बढ़ावा देने के लिए हमारे देश की सरकारी एजेंसियाँ सतत् क्रियाशील हैं। लखनऊ स्थित केन्द्रीय औषध अनुसंधान संस्थान (Central Drug Research Institue CDRI) ने “सहेली” नामक गर्भनिरोधक गोली का निर्माण किया है। यौन संचारित रोगों की सही जाँच तथा देखभाल और लगभग सभी जनन स्वास्थ्य समस्याओं हेतु विकसित चिकित्सा सुविधाओं के होने से बेहतर समाज एवं जनन स्वास्थ्य के संकेत प्राप्त हो रहे हैं।

प्रश्न 3.
क्या विद्यालयों में यौन शिक्षा आवश्यक है ? यदि हाँ तो क्यों ?
उत्तर
हाँ, विद्यालयों में यौन शिक्षा आवश्यक है, ताकि छात्र/छात्राओं को यौन संबंधी विभिन्न पहलुओं के बारे में फैली हुई भ्रान्तियों एवं यौन संबंधी गलत धारणाओं से छुटकारा मिल सके। बच्चों को जनन अंगों, किशोरावस्था एवं उससे संबंधित परिवर्तनों, सुरक्षित और स्वच्छ यौन क्रियाओं, यौन संचारित रोगों एवं एड्स की जानकारी देना विशेष रूप से किशोर आयु वर्ग में जनन संबंधी स्वस्थ जीवन बिताने में सहायक होती है।

प्रश्न 4.
क्या आप मानते हैं कि पिछले 50 वर्षों के दौरान हमारे देश के जनन स्वास्थ्य में सुधार हुआ है? यदि हाँ तो इस प्रकार के सुधार वाले कुछ क्षेत्रों का वर्णन कीजिए।
उत्तर
जी हाँ, पिछले 50 वर्षों के दौरान हमारे देश के जनन स्वास्थ्य क्षेत्र में सुधार हुआ है। निम्न क्षेत्रों में हुए सुधार को आसानी से देखा जा सकता है

1. यौन संबंधी मामलों के बारे में बेहतर जागरुकता आयी है।
2. चिकित्सकीय देख-रेख में होने वाले प्रसवों की संख्या में वृद्धि हुई है।
3. प्रसवोत्तर देखभाल बेहतर हुई है।
4. मातृ मृत्यु-दर (MMR) में गिरावट आई है।
5. शिशु मृत्यु-दर (IMR) में गिरावट आई है।
6. यौन संचारित रोगों की सही जाँच-पड़ताल तथा देखभाल व उपचार बेहतर हुआ है।
7. जनसंख्या वृद्धि दर पर रोक लगी है।
   कुल मिलाकर सभी यौन समस्याओं हेतु बढ़ी हुई चिकित्सा सुविधाओं का होना समाज के बेहतर जनन स्वास्थ्य की ओर संकेत देता है।

प्रश्न 5.
जनसंख्या विस्फोट के कौन-से कारण हैं ?
उत्तर
शीघ्र एवं अनियमित जनसंख्या वृद्धि को जनसंख्या विस्फोट कहा जाता है।इसके प्रमुख कारण निम्नलिखित हैं

1. रोगों व महामारियों पर नियंत्रण
2. कृषि का विकास
3. संचार व आवागमन के साधन
4. उच्च जन्मदर
5. निम्न मृत्युदर
6. मनुष्य का वर्ष भर मैथुनकाल होना।

प्रश्न 6.
क्या गर्भ-निरोधकों का उपयोग न्यायोचित है ? कारण बताइए।
उत्तर
भारत में जनसंख्या वृद्धि-दर अत्यधिक होने के कारण राष्ट्रीय संकट उत्पन्न हो गया है। अतः गर्भ निरोधकों का उपयोग न्यायोचित है। इसके उपयोग से परिवार को सीमित किया जा सकता है एवं उनकी सुविधाओं में वृद्धि की जा सकती है। इन गर्भ निरोधकों के उपयोग से यौन संचारित रोगों (STDs) से बचा जा सकता है। इसके साथ ही दो संतानों के बीच अन्तराल भी रखा जा सकता है।जनसंख्या वृद्धि को कम करके परिवार, समाज व देश की समृद्धि में सहयोग कर सकते हैं।

प्रश्न 7.
जनन ग्रंथि को हटाना, गर्भ निरोधकों का विकल्प नहीं माना जा सकता है, क्यों?
उत्तर
जनन ग्रंथियाँ सन्तान उत्पन्न करने वाले अंग हैं । वृषण में शुक्राणुओं तथा अण्डाशय में अण्डों का निर्माण होता है। गर्भ निरोधक के लिए स्वस्थ अंगों को शरीर से हटाना उचित नहीं है। इससे मानसिक, शारीरिक स्वास्थ्य संबंधी समस्याएँ उत्पन्न हो सकती हैं। जबकि गर्भ निरोधक विधियाँ सुलभ होती हैं एवं उनका कोई बुरा प्रभाव भी शरीर पर नहीं पड़ता है। इनका आसानी से प्रयोग भी किया जा सकता है। जरूरत पड़ने पर इसे हटाया भी जा सकता है। जनन ग्रंथि को हटाना एक जटिल प्रक्रिया है, कानून हमें इसकी आज्ञा भी नहीं देता है।

प्रश्न 8.
उल्बवेधन एक घातक लिंग निर्धारण (जाँच) प्रक्रिया है, जो हमारे देश में निषेधित है। क्या यह आवश्यक होना चाहिए ? टिप्पणी कीजिए।
उत्तर
बढ़ती मादा भ्रूण हत्या की कानूनी रोक के लिए उल्बवेधन (Amniocentesis) जाँच (भ्रूणीय लिंग निर्धारण), लिंग परीक्षण पर वैधानिक प्रतिबंध उचित है क्योंकि यह एक खतरनाक प्रवृत्ति है। कई बार ऐसा देखा जाता है कि यह पता चलने पर कि भ्रूण मादा (लड़की) है, चिकित्सीय सगर्भता समापन (Medical termination of pregnancy) कराया जाता है, सामान्य भाषा में इसे गर्भपात (Abortion) कहा जाता है। यह पूरी तरह गैर-कानूनी है। इस प्रकार की प्रवृत्ति से बचना चाहिए क्योंकि यह माता एवं बच्चा (भ्रूण) दोनों के लिए खतरनाक है । इससे समाज में पुरुष एवं महिलाओं की संख्या का अनुपात भी बिगड़ सकता है। जिससे वैवाहिक तथा स्वास्थ्य संबंधी समस्याएँ भी उत्पन्न हो सकती हैं।

प्रश्न 9.
बन्ध्य दम्पत्तियों को संतान पाने हेतु सहायता देने वाली कुछ विधियाँ बताइए।
उत्तर
यदि दंपत्ति बच्चा पैदा करने में अक्षम है तथा ऐसे दोष को ठीक करने का इलाज संभव न हो तो कुछ विशेष तकनीकों के द्वारा उन्हें बच्चा पैदा करने में सहायता की जा सकती है, ये तकनीकें सहायक जनन प्रौद्योगिकी (ART) कहलाती हैं।
1. पात्रे निषेचन (Invitro fertilization IVF)-
इस विधि में अण्डाणु का निषेचन शरीर से बाहर लगभग शरीर के भीतर जैसी स्थिति में कराया जाता है। इसके पश्चात् स्त्री में भ्रूण स्थानान्तरण (Embryo transfer, ET) कराया जाता है।

• युग्मनज डिंबवाहिनी स्थानान्तरण (Zygote intrafallopian transfer ZIFT)-इस प्रक्रिया में प्रारंभिक भ्रूण को 8 ब्लास्टोमियर तक की अवस्था में स्त्री की डिंबवाहिनी या फैलोपियन नलिका में अग्रिम परिवर्धन के लिए स्थानांतरित किया जाता है।
• आन्तर गर्भाशयी स्थानान्तरण (Intrauterine transfer IUT)-जब भ्रूण को 8 ब्लास्टोमियर से अधिक अवस्था पर परिवर्तन हेतु स्त्री के गर्भाशय में स्थानान्तरित किया जाता है तो इसे IUT कहते हैं । यदि किसी स्त्री में गर्भधारण नहीं हो पाता है तो उसकी सहायता के लिए पात्रे निषेचन अर्थात् अन्य स्त्री के भीतर ही निषेचन कराने के बाद भ्रूण को उस स्त्री में स्थानान्तरित किया जा सकता है।
• टेस्ट ट्यूब बेबी (Test tube baby)-इस विधि में दाता स्त्री के अण्डे को दाता पुरुष शुक्राणु से प्रयोगशाला में परखनली के भीतर (स्त्री शरीर के बाहर) निषेचन कराया जाता है तथा निश्चित समय तक अनुरूपी परिस्थितियों में परिवर्धन के बाद अग्रिम परिवर्धन हेतु स्त्री के गर्भाशय में स्थानान्तरित कर दिया जाता है। इस विधि द्वारा जन्मे बच्चे को “टेस्ट ट्यूब बेबी” कहते हैं।

2. युग्मक आन्तर फैलोपीयन स्थानान्तरण (Gamete intrafallopian transfer GIFT)-
जिन स्त्रियों में अण्डाणु उत्पन्न नहीं होता है किन्तु इनमें निषेचन और भ्रूण परिवर्धन के लिए उचित वातावरण होता है उनमें यह विधि अपनायी जाती है। इसमें एक दाता स्त्री से अण्डाणु लिया जाता है तथा उस स्त्री को फैलोपीयन नलिका में स्थानांतरित कर दिया जाता है।

3. आन्तर कोशिकीय शुक्राणु निक्षेपण (Intra-cytoplasmic sperm injection)-
प्रयोगशाला में भ्रूण बनाने के लिए इस प्रक्रिया में शुक्राणु को सीधे ही अण्डाणु में अंत:क्षेपित कर दिया जाता है।

4. कृत्रिम वीर्य सेचन (Artificial insemination AI)-
यदि पुरुष-स्त्री को वीर्य सेचित करने में अक्षम हो अथवा उसके वीर्य में शुक्राणुओं की संख्या कम हो तो ऐसी अवस्था में यह तकनीक अपनायी जाती है। इस विधि में पति अथवा एक स्वस्थ दाता का वीर्य कृत्रिम रूप से स्त्री की योनि में प्रविष्ट कर दिया जाता है। जब कृत्रिम विधि से वीर्य को गर्भाशय में प्रविष्ट किया जाता है तो इसे गर्भाशय वीर्य सेचन (Intra-uterine insemination IUI) कहते हैं।

5. परपोषी मातृत्व (Host mothering)-
इस विधि में भ्रूण को प्राकृतिक माता से निकालकर एक अन्य स्त्री धात्रेय माता (Foster mother) में रोपित कर दिया जाता है। धात्रेय माता में यह भ्रूण जन्म तक अथवा अस्थायी रूप से निश्चित समय तक वर्धित होता है। जिसके बाद इन्हें पुनः मूल माता में या अन्य किसी स्त्री में रोपित कर दिया जाता है। यह तकनीक ऐसी स्त्रियों के लिए लाभदायक है जिनमें भ्रूण बन तो जाता है किन्तु पूर्ण परिवर्धन के समय तक ये इसे रख नहीं पाती हैं।

प्रश्न 10.
किसी व्यक्ति को यौन संचारित रोगों की चपेट में आने से बचने के लिए कौन-से उपाय अपनाने चाहिए?
उत्तर
यौन संचारित रोगों से बचाव (Protection from Sexually Transmitted Diseases)यौन संचारित रोगों से बचाव हेतु निम्न बातों का ध्यान रखना चाहिए

1. किसी अनजान व्यक्ति या बहुत से व्यक्तियों के साथ यौन संबंध न रखें।
2. मैथुन के समय हमेशा कंडोम का इस्तेमाल करें।
3. संक्रमित व्यक्ति का रुधिर किसी अन्य व्यक्ति को न चढ़ाया जावे।
4. पहले से उपयोग किये गये इंजेक्शन व सुईयों का प्रयोग न करें।
5. समलैंगिकता से बचें।
6. यदि कोई आशंका है तो तुंरत ही प्रारंभिक जाँच के लिए किसी योग्य चिकित्सक से मिलें और रोग की पहचान होने पर पूरा इलाज करावें।

प्रश्न 11.
निम्न वाक्य सही है या गलत, व्याख्या सहित बताइए

(क) गर्भपात स्वतः भी हो सकता है। (सही/ गलत)
उत्तर
गलत, सामान्य परिस्थितियों में गर्भपात नहीं होता। किसी दुर्घटनावश या स्वैच्छिक रूप से गर्भसमापन (गर्भपात) होता है।

(ख) बंध्यता को जीवनक्षम संतति न पैदा कर पाने की अयोग्यता के रूप में परिभाषित किया गया है और यह सदैव स्त्री की असामान्यताओं/दोषों के कारण होती है।(सही/गलत)
उत्तर
गलत, बंध्यता हमेशा स्त्री की असामान्यताओं/ दोषों के कारण नहीं होती, कभी-कभी पुरुष भी बंध्यता के लिए दोषी होता है।

(ग) एक प्राकृतिक गर्भ निरोधक उपाय के रूप में शिशु को पूर्णरूप से स्तनपान कराना सहायक होता है। (सही/गलत)
उत्तर
सही, शिशु को पूर्णरूप से स्तनपान कराने से अण्डोत्सर्ग नहीं होता है। अतः आर्तव चक्र (Menstrual cycle) भी नहीं होता है, जिसके कारण गर्भ की संभावनाएँ समाप्त हो जाती हैं। किन्तु यह विधि शिशु के जन्म के अधिकतम 6 माह तक कारगर है।

(घ) लोगों के जनन स्वास्थ्य के सुधार हेतु यौन संबंधित पहलुओं के बारे में जागरुकता पैदा करना एक प्रभावी उपाय है।(सही/गलत)
उत्तर
सही, क्योंकि ऐसा करने से लोगों की जनन स्वास्थ्य की समस्याएँ समाप्त अथवा कमतर हो जाती हैं।

प्रश्न 12.
निम्नलिखित प्रश्नों को सही कीजिए

(क) गर्भ निरोधक के शल्य क्रियात्मक उपाय युग्मक बनने को रोकते हैं।
उत्तर
युग्मक बनने से नहीं, बल्कि युग्मकों के परिवहन को रोकते हैं।

(ख) सभी प्रकार के यौन संचारित रोग पूरी तरह उपचार योग्य हैं।
उत्तर
हिपेटाइटिस-B, एड्स एवं जननिक हर्पिस का उपचार नहीं होता।

(ग) ग्रामीण महिलाओं के बीच गर्भ निरोधक के रूप में गोलियाँ (पिल्स) बहुत अधिक लोकप्रिय
उत्तर
ग्रामीण महिलाओं में गर्भ निरोधक के रूप में गोलियाँ (पिल्स)लोकप्रिय नहीं हैं । ग्रामीण महिलाओं को यौन शिक्षा की आवश्यकता है।

(घ) ई. टी. तकनीकों में भ्रूण को सदैव गर्भाशय में स्थानान्तरित किया जाता है।
उत्तर
ई. टी. तकनीकों में 8 ब्लास्टोमियर से ज्यादा अवस्था वाले भ्रूण को गर्भाशय में स्थानान्तरित किया जाता है। जबकि 8 ब्लास्टोमियर से कम अवस्था वाले भ्रूण को अण्डवाहिनी में स्थानान्तरित किया जाता है।

जनन स्वास्थ्य अन्य महत्वपूर्ण प्रश्नोत्तर

जनन स्वास्थ्य वस्तुनिष्ठ प्रश्न

1. सही विकल्प चुनकर लिखिए-

प्रश्न 1.
स्त्रियों के शरीर से फैलोपियन ट्यूब को अलग करना कहलाता है
(a) वैसेक्टोमी
(b) ट्यूबेक्टोमी
(c) ओवरीक्टोमी
(d) कैस्ट्रेशन।
उत्तर
(b) ट्यूबेक्टोमी

प्रश्न 2.
आबादी की सर्वाधिक वृद्धि का प्रमुख कारण है
(a) कम मृत्यु दर
(b) जन्मदर में वृद्धि
(c) अकाल न पड़ना
(d) युद्ध कम होना।
उत्तर
(a) कम मृत्यु दर

प्रश्न 3.
बड़े शहरों में अधिक जनसंख्या का कारण है
(a) शिक्षा के अवसर
(b) उपलब्ध भौतिक सुविधाएँ
(c) अधिक आय के स्रोत
(d) उपर्युक्त सभी।
उत्तर
(d) उपर्युक्त सभी।

प्रश्न 4.
जनसंख्या घनत्व अधिक है____
(a) यू.एस.ए. में
(b) भारत में
(c) चीन में
(d) जापान में।
उत्तर
(c) चीन में

प्रश्न 5.
AIDS रोग फैलता है
(a) बैक्टीरिया से
(b) प्रोटोजोआ से
(c) वाइरस से
(d) फंगस से।
उत्तर
(c) वाइरस से

प्रश्न 6.
यौन संक्रमित रोगों के कारक होते हैं
(a) विषाणु
(b) जीवाणु
(c) प्रोटोजोआ
(d) उपर्युक्त सभी।
उत्तर
(a) विषाणु

प्रश्न 7.
भारत में जनसंख्या की गणना की गई थी
(a) सन् 1891
(b) सन् 1947
(c) सन् 1950
(d) सन् 1961.
उत्तर
(a) सन् 1891

प्रश्न 8.
निम्न में से जन्मदर को नियंत्रित करने की विधि
(a) TUD
(b) GIFT
(c) MIF
(d) IVEET
उत्तर
(a) TUD

प्रश्न 9.
एल्कोहॉल से सर्वाधिक प्रभावित अंग है
(a) यकृत
(b) सेरीब्रम
(c) सेरीबेलम
(d) हृदय।
उत्तर
(a) यकृत

प्रश्न 10.
विश्व की जनसंख्या वृद्धि दर है
(a) 2.4%
(b) 2%
(c) 3%
(d) 4%.
उत्तर
(b) 2%

2. रिक्त स्थानों की पूर्ति कीजिए

1. मानव जनसंख्या का सांख्यिकीय अध्ययन ………………. कहलाता है।
2. माल्थस के अनुसार जनसंख्या में ………………. वृद्धि होती है जबकि खाद्य उत्पादन में ……………….. वृद्धि होती है।
3. किसी समष्टि में एक निश्चित अवधि में जीवों का आना और बाहर जाना ………………. कहलाता
4. शुक्राणु नली को काटकर बन्द करना ………………. कहलाता है।
5. स्थलीय जीवों के जनसंख्या घनत्व के लिये स्थान के क्षेत्रफल को ……………… से प्रदर्शित करते हैं।
6. जन्मदर एवं अप्रवासन जनसंख्या घनत्व में ………………. करते हैं।
7. संशोधित जन्मदर ……………… जन्मदर से अधिक होती है।
8. जनसंख्या आकार को नियन्त्रित करने वाले कारक को …………….. कहते हैं।
9. जैव सूचकांक = ( ………………. / मृत्युदर) x 1000.
10. बालिकाओं में बालकों की अपेक्षा ……………. परिपक्वता आती है।
11. भारत पहला देश है जिसने …………………… स्वास्थ्य देखभाल को ………………….में सामाजिक लक्ष्य के रूप में लाया।
12. RCH भारत में .. ……………. में लाया गया।
13. एम्नियोसेन्टेसिस में लिंग निर्धारण …………. गुणसूत्र के निरीक्षण द्वारा लाया गया।
14. प्रसव के ठीक बाद महिलाएँ …… अनार्तव (मासिक धर्म amoeriorrhoea) का अनुभव करती हैं।
15. LNG-20 ……………….. स्रावी IUD है।
उत्तर

1. डेमोग्राफी
2. बीजगणितीय, अंकगणितीय
3. प्रवासन
4. वैसेक्टोमी
5. द्विविमा (m²)
6. वृद्धि,
7. अशोधित
8. धनात्मक अवरोधक
9. जन्मदर
10. जल्दी
11. प्रजनन, सन् 1951
12. सन् 1997,
13. लिंग
14. स्तनपान संबंधी
15. हॉर्मोन।

3. सही जोड़ी बनाइए

‘A’ – ‘B’

1. S-आकृति वक्र – (a) जन्म नियंत्रण विधि
2. kसीमा स्थिरांक – (b) जनसंख्या
3. शुक्राणु नाशक रसायन – (c) लॉजिस्टिक वक्र
4. माल्थस 2009 – (d) D/Px1000
5. वास्तविक मृत्युदर – (e) संतृप्ति अवस्था।
उत्तर
1.(c), 2.(e), 3.(a), 4. (b), 5.(d).

‘A’ – ‘B’

1. माल्थस – (a) कॉपर-टी
2 वैसेक्टोमी – (b) लिंग परीक्षण
3. ट्यूबेक्टोमी – (c) सेन्सस
4. जनगणना – (d) जनसंख्या पर निबंध
5. एम्निओसेण्टेसिस – (e) पुरुष
6. आई.ग.सी.डी. – (f) स्त्री या जनसंख्या नियंत्रण।
उत्तर
1.(d),2.(e),3. (1), 4.(c), 5.(b), 6.(a).

4. एक शब्द में उत्तर दीजिए

1. दो ऐसे कारण दीजिए जिनसे जनसंख्या अनियन्त्रित रूप से बढ़ जाती है।
2. IUCD का पूरा नाम लिखिए।
3. मानव जनसंख्या का अध्ययन क्या कहलाता है?
4. माला D और N में कौन-सा रासायनिक गर्भ-निरोधक पाया जाता है ?
उत्तर

1. (i) कम उम्र में विवाह, (ii) शिक्षा
2. इन्ट्रायूरिक कन्ट्रासेप्टिव डिवाइसेस
3. डेमोग्राफी (Demography)
4. एस्ट्रोजन एवं प्रोजेस्टीरॉन हॉमोन।

जनन स्वास्थ्य अति लघु उत्तरीय प्रश्न

प्रश्न 1.
परिवार नियोजन को अब किस नाम से जाना जाता है ?
उत्तर
परिवार नियोजन को अब “परिवार कल्याण” के नाम से जाना जाता है।

प्रश्न 2.
सेन्ट्रल ड्रग रिसर्च इन्स्टीट्यूट (CDRI) कहाँ अवस्थित है।
उत्तर
लखनऊ (उत्तरप्रदेश) में स्थित है।

प्रश्न 3.
कंडोम के उपयोग के कोई एक लाभ लिखिए।
उत्तर
कंडोम यौन संचरित रोगों से बचाव करता है।

प्रश्न 4.
हफ्ते में एक बार लेने वाली गर्भनिरोधक गोली का नाम लिखिए।
उत्तर
“सहेली”

प्रश्न 5.
IUCD काशब्द विस्तार बताइए।
उत्तर
इन्ट्रा यूटेराइन कॉन्ट्रासेप्टिव डिवाइस।

प्रश्न 6.
STD का सम्पूर्ण रूप लिखिये।
उत्तर
यौन संचारित रोग (Sexually Transmitted Diseases)।

प्रश्न 7.
विवाह की वैधानिक आयु स्त्री और पुरुष के लिए क्या सुनिश्चित है ?
उत्तर
स्त्री की आयु 18 वर्ष तथा पुरुष के लिए 21 वर्ष सुनिश्चित है।

प्रश्न 8.
दो STD के नाम लिखिए जो संदूषित रक्त से संचारित होते हैं।
उत्तर
(a) एड्स
(b) हिपेटाइटिस-BI

प्रश्न 9.
लैंगिक संपर्क से होने वाले कोई दो रोग बताइए।
उत्तर

• सूजाक (Gonorrhoea)
• सिफलिस (Syphilis)

प्रश्न 10.
HIV एवं AIDS का सम्पूर्ण रूप लिखिए।
उत्तर

• HIV—ह्यूमन इम्यूनोडेफीसिएन्सी वाइरस।
• AIDS- एक्वायर्ड इम्यूनोडेफीसिएन्सी सिन्ड्रोम।

प्रश्न 11.
ZIFT का पूरा नाम लिखिए।
उत्तर
युग्मनज अन्तः डिम्बवाहिनी स्थानान्तरण (Zygote Intra-fallopian Transfer)।

प्रश्न 12
पुरुष में नसबंदी की शल्य क्रिया का क्या नाम है ?
उत्तर
वैसेक्टोमी (Vasectomy)।

प्रश्न 13.
दो ऐसे कारण दीजिये जिनसे जनसंख्या अनियन्त्रित रूप से बढ़ जाती है।
उत्तर
रोगों का नियंत्रण, कृषि का विकास।

प्रश्न 14.
मानव जनसंख्या का अध्ययन क्या कहलाता है ?
उत्तर
डेमोग्राफी।

प्रश्न 15.
माला D और N में कौन-सा रासायनिक गर्भ निरोधक पाया जाता है ?
उत्तर
एस्ट्रोजन एवं प्रोजेस्ट्रॉन।

प्रश्न 16.
एम्नियोसेण्टेसिस विधि द्वारा किसका परीक्षण किया जाता है ?
उत्तर
भ्रूण का लिंग परीक्षण।

प्रश्न 17.
किसी इकाई क्षेत्रफल में पाई जाने वाली मानव संख्या कहलाती है ?
उत्तर
जनसंख्या घनत्व।

जनन स्वास्थ्य लघु उत्तरीय प्रश्न

प्रश्न 1.
परखनली शिशु कैसे प्राप्त किये जा सकते हैं ?
उत्तर
स्त्रियाँ जब गर्भधारण करने योग्य नहीं होती हैं, उस स्थिति में परखनली शिशु तकनीक का उपयोग किया जाता है। स्त्रियों के अनिषेचित अण्डाणु को ऐण्टिसेप्टिक स्थिति में निकाला जाता है। इस अण्डाणु को परखनली में लेकर शुक्राणु द्वारा निषेचन (Fertilization) की क्रिया कराते हैं । निषेचित अण्डाणु से विदलन क्रिया द्वारा 32 कोशिकीय अवस्था वाला भ्रूण बनता है, जिसे ब्लास्टोसिस्ट (Blastocyst) कहते हैं। इस 32 कोशिकीय भ्रूण का रोपण स्त्रियों के गर्भाशय में कर दिया जाता है जहाँ पर इस भ्रूण का अगला विकास होता है और शिशु बनता है जिसे ‘टेस्ट ट्यूब बेबी’ कहते हैं।

प्रश्न 2.
गिफ्ट (GIFT) क्या है ?
उत्तर
GIFT-इसका पूरा नाम गैमीट इन्ट्रा फैलोपियन ट्रान्सफर (Gamete Intra Fallopian Transfer) है । यह गर्भ निरोधन की आधुनिक तकनीक है। इस तकनीक में शुक्राणु कैथेटर (Catheter) में संगृहीत कर लिया जाता है। वाश स्विम तकनीक (Wash swim up technique) द्वारा शुक्राणुओं को अण्डाणु के पीछे कैथेटर में संगृहीत किया जाता है। यह सम्पूर्ण क्रिया स्त्रियों की फैलोपियन नलिका में होती है। निषेचन क्रिया शुक्राणुओं की संख्या कम होने से पूर्ण नहीं हो पाती है।

प्रश्न 3.
ट्यूबेक्टोमी और वैसेक्टोमी को समझाइये।
उत्तर
ट्यूबेक्टोमी-इसमें स्त्री की अण्डवाहिनी को काटकर बाँध दिया जाता है। जिससे अण्डाणु गर्भाशय में नहीं आ पाते और निषेचन नहीं हो पाता। इसे ट्यूबेक्टोमी कहते हैं। यह परिवार नियोजन की एक विधि है। वैसेक्टोमी-यह भी परिवार नियोजन की एक विधि है जो पुरुषों द्वारा अपनाई जाती है। इसमें पुरुष की शुक्राणु नलिका को काटकर बाँध दिया जाता है जिससे शुक्राणु स्खलन के समय नहीं निकलते और निषेचन नहीं हो पाता। यह क्रिया वैसेक्टोमी कहलाती है।

प्रश्न 4.
एम्नियोसेण्टेसिस क्या है ?
उत्तर
एम्नियोसेण्टेसिस भ्रूण परीक्षण की एक तकनीक है जिसमें सर्जिकल सुई द्वारा मादा के गर्भाशय से एम्नियोटिक द्रव को शरीर से बाहर निकाला जाता है और एम्नियोटिक द्रव में उपस्थित फोयटस कोशा का संवर्धन किया जाता है और इसका गुणसूत्रीय परीक्षण करके निम्न बातों का पता लगाया जाता है

• गुणसूत्रीय असामान्यता, जैसे-डाउन सिण्ड्रोम, फिलोडेल्फिया सिण्ड्रोम एवं एडवर्ड सिण्ड्राम।
• उपापचयी अनियमितताएँ, जैसे- PKU, क्रिटेनिज्म, एल्केप्टोन्यूरिया।
• लिंग भ्रूण के परीक्षण में इसका उपयोग किया जाता है।

प्रश्न 5.
मानव जनसंख्या वृद्धि के सामाजिक कारण समझाइये।
उत्तर
मानव जनसंख्या वृद्धि के प्रमुख सामाजिक कारण निम्नलिखित हैं

• समाज का अशिक्षित होना ।
• निम्न सामाजिक स्तर का होना।
• समाज में विभिन्न प्रकार की कुरीतियाँ होना।
• विभिन्न प्रकार की सामाजिक मान्यताएँ ।
• कम उम्र में विवाह करना, क्योंकि उम्र के पूर्वार्द्ध में प्रजनन क्षमता अधिक होती है।
• निम्न सामाजिक स्तर के कारण मनोरंजन का अभाव होना।
• सामाजिक मान्यताएँ जैसे-पुत्र रत्न की प्राप्ति से मोक्ष मिलता है
• सामाजिक पिछड़ापन।

MP Board Class 12th Biology Solutions

MP Board Class 12th Chemistry Solutions Chapter 6 General Principles and Processes of Isolation of Elements

General Principles and Processes of Isolation of Elements NCERT Intext Exercises

Question 1.
Which of the ores mentioned in Table 6.1? Can be concentrated by magnetic separation method?
Answer:
Ores in which one of the components (either the impurity or the ore) is magnetic can be concentrated by magnetic separation method, e.g. Haematite (Fe₂O₂), magnetite (Fe₃O₄), siderite (FeCO₃), iron pyrites (FeS) and copper pyrites (CuFeS₂) can be concentrated by magnetic separation method.

Question 2.
What is the significance of leaching in the extraction of aluminium?
Answer:
Main ore of aluminum is bauxite (Al₂O₃ xH₂O). It contains the impurities of SiO₂, FeO, and Titanium oxide (TiO₂). These impurities are removed by Leaching. The significance of leaching is to prepare pure alumina from bauxite. The powdered bauxite ore is heated with NaOH solution at 473 – 523K. Alumina dissolves as sodium meta aluminate whereas impurities of iron and titanium remain behind.

The impurities are filtered off. The filtrate is neutralized by passing CO₂. Aluminium hydroxide separates out while sodium silicate remains in the solution. Aluminium hydroxide on heating gives pure alumina.

Question 3.
The reaction, Cr₂O₃ + 3Al → Al₂O₃ + 2Cr; (∆°G = -421 kJ) is thermodynamically feasible as is apparent from Gibb’s energy value. Why does it not take place at room temperature?
Answer:
Since ∆G is negative, the reaction is feasible. But a certain amount of activation energy is required for this reaction to occur and hence it will not take place at room temperature (heating is required).

Question 4.
Is it true that under certain conditions, Mg can reduce SiO₂ and Si can reduce MgO? What are those conditions?
Answer:
Mg can reduce SiO₂ below or at 1693K. Silicon can reduce MgO above 1693K.

General Principles and Processes of Isolation of Elements NCERT Text Book Exercises

Question 1.
Copper can be extracted by hydrometallurgy but not zinc. Explain.
Answer:
The E° of zinc (Zn²⁺ / Zn = -0.76v) or iron (Fe²⁺ / Ee = -0.44v) is lower than that of copper (Cu²⁺ / Cu = + 0.34v) and hence both Zn and Fe, can displace Cu from solutions of Cu²⁺ ions. Although zinc is a stronger reducing agent than iron, yet iron scrap is chiefty used in hydrometallurgy of copper because it is much cheaper than zinc.

Fe (s) + Cu²⁺ (aq) → Fe²⁺ (aq) + Cu (s)

In contrast, to displace zinc from solution of Zn²⁺ ions, we need more reactive metal than it, i.e A1 (E° Al³⁺/ Al = -1.66v), Mg (e ° Mg²⁺ / Mg = -2.37v), Ca (e ° Ca²⁺ / Ca = -2.87) K . (e ° k⁺ / k = -2.93 v) etc.

But all these metals react with water [2H₂ + 2e^– → H₂(g) + 20n- (ag), = -0.83v] forming their corresponding ions with the evolution of H₂ gas.
Thus, Al, Mg etc cannot be used to displace zinc from solution of Zn²⁺ ions. Thus copper can be extracted by hydrometallurgy but not zinc.

Question 2.
What is the role of depressant in froath floatation process?
Answer:
It prevents one of the components from forming the froth by complexation. e.g. Sodium cyanide acts as a depressant for ZnS but does not prevent PbS from froth formation during the separation of zinc sulphide ores from lead sulphide ores.

Question 3.
Why is the extraction of copper from pyrites more difficult than that from its oxide ore through reduction ?
Answer:
The standard free energy (∆_f G°) of formation of Cu₂S is greater than those of CS₂ and H₂S (CS₂ is infact, an endothermic compound) Therefore neither carbon nor hydrogen can reduce Cu₂S to Cu metal.

Cu₂S + H₂ > 2Cu + H₂S
2Cu₂S + C > 4Cu + CS₂

In contrast, ∆_fG° of Cu₂0 is much lower than that of CO and hence carbon can easily reduce Cu₂O to Cu.

Cu₂O (S) + C (S) → 2 Cu (S) + CO (g)

It is because of this reason that the extraction of copper from pyrite is difficult than from its oxide ore through reduction.

Question 4.
Explain
(i) Zone refining
(ii) Column chromatography.
Answer:
(i) Zone refining (Fractional crystallization): This method is used to prepare metals in an extremely pure state. Boron, gallium, indium, silicon, germanium, etc. are purified by this method. This method is based on the fact that when molten impure metal is allowed to cool, the pure metal crystallizes out whereas the impurities remain behind in the melt.

Method: A thin bar of impure metal is taken. One zone of the bar is heated with a moving circular heater in the atmosphere of inert gas. A narrow zone of the metal is melted. The pure metal crystallizes out of the melt while the impurities move into the adjacent molten zone.

The process is repeated several times till the impurities are completely driven to one end and the pure metal towards the other end. Then end of the rod where the impurities have collected is cut off. The metal obtained is extremely pure.

(ii) Column chromatography: In column chromatography, a suitable adsorbent such as alumina (Al₂O₃) is packed in glass tube having a stop-cock near the bottom. This constitutes the stationary phase. The mixture to be separated is dissolved in some suitable solvents and added to the column. The different components of the mixture get adsorbed to different extent. Some suitable solvent (called eluent) is then added to the column. The eluent constitute the mobile phase. The weakly adsorbed component reaches the bottom of the column first.

It is followed by more strongly adsorbed components. Thus, different components of the mixture reach the bottom one by one and in this way get separated. This method is suitable for purification of those elements which are available in small quantities and the impurities are not much different in chemical behaviour from the element to be purified. Lanthanoides (rare earth elements) are purified by this technique.

Question 5.
Out of C and CO, which is a better reducing agent at 673 K?
Answer:
At 673K, the value of ∆G (CO, CO₂) is less than that of ∆G (C, CO) therefore, CO can be reduced more easily to CO₂ than C to , CO. Hence CO is a better reducing agent than ‘ C at 673K.

Question 6.
Name the common elements present in the anode mud in electrolytic refining of copper. Why are they so present?
Answer:
Selenium, tellurium, silver, gold are the metals present in anode mud. This is because these are less reactive than copper.

Question 7.
Write down the reactions taking place in different zones in the blast furnace during the extraction of iron.
Answer:
Reactions in blast furnace :
(i) Coke burns in presence of air to form CO₂ in excess of CO is formed.

(ii) CO reduces haematite ore (Fe₂O₃) to ferric oxide (FeO) at 600°C.
CO + Fe₂O₃ → 2 FeO + CO₂
(iii) About 750°C CO reduces FeO into Fe.
FeO + CO → Fe + CO₂
(iv) At 110° CaCO₃ decomposes into CaO.
CaCO₃ → CaO + CO₂
This way the iron sobtained is called spongy iron.
(v) CaO reacts with silica present in ore and form slag.
CaO + SiO₂ → CaSiO₃
calcium silicate
Slag floats over molten iron from where it is removed through the tapping hole.
Labelled diagram of blast furnace :

Question 8.
Write chemical reactions taking place in the extraction of zinc from zinc blende.
Answer:
Zinc oxide is obtained from zinc blende, then zinc is extracted from zinc oxide. The whole process is described below :
The zinc blende (ZnS) ore is concentrated by froth floatation process, then roasted to give oxide.
2ZnS + 2O₃ → 2ZnO + 2SO₂ ↑
The zinc oxide is mixed with coke and clay to make bricketters. These bricketters are heated at 1673 K to give zinc. The temperature in this case is higher than that in case of copper.

The metal is distilled off and collected by rapid chilling.
(Note : For detail, refer to Other Important Long Ans. Type Q. No. 7.)

Question 9.
State the role of silica in the metallurgy of copper.
Answer:
Silica acts as acidic flux in order to remove basic impurity of iron oxide.

Question 10.
What is meant by the term “Chromatography”?
Answer:
This method is used for the purification of the elements which are available in minute quantities and the impurities are not very different in chemical properties from the element to be purified. This method is based on the principle that different components of a mixture arc differently adsorbed on an adsorbent.

In column chromatography, an adsorbent (e.g. silica gel. Al₂O₃ etc.) is packed in a glass column. The mixture to be separated and purified, taken in a suitable solvent, is applied on the top of the column. The components of the mixture get adsorbed on the column. They are then eluted out with a suitable chiant (solvent). The weakly adsorbed component is eluted first fòllowed by the more strongly adsorbed and so on.

Question 11.
What criterion is followed for the selection of the stationary phase in chromatography?
Answer:
The stationary phase is selected in such a way that the impurities are more strongly absorbed or are more soluble in the stationary phase than element to be purified. Under these conditions, when the column is extracted, the impurities will be retained by the stationary phase while the pure components is easily eluted.

Question 12.
Describe a method for refining nickel.
Answer:
Mond’s process is useful for refining nickel. The impure metal is heated with CO at 60° – 80° C. The metal reacts with CO to form gaseous metal carbonyls leaving behind solid impurities. The pure metal is recovered from the metal carbonyl by heating the gas at 180 – 200°C.

Question 13.
How can you separate alumina from silica in bauxite ore associated with silica? Give equations, if any.
Answer:
Main ore of aluminium is bauxite (Al₂O₃ xH₂O). It contains the impurities of SiO₂, FeO and Titanium oxide (TiO₂). These impurities are removed by Leaching. The significance of leaching is to prepare pure alumina from bauxite. The powdered bauxite ore is heated with NaOH solution at 473 – 523K. Alumina dissolves as sodium meta aluminate whereas impurities of iron and titanium remain behind.

The impurities are filtered off. The filtrate is neutralized by passing CO₂. Aluminium hydroxide separates out while sodium silicate remains in the solution. Aluminium hydroxide on heating gives pure alumina.

Question 14.
Giving examples, differentiate between ‘Roasting’ and ‘Calcination’.
Answer:
Roasting is the process of converting an ore into metallic oxide by heating strongly in excess of air.
ZnS + 3O₂ → 2ZnO + 2SO_2(g)
Calcination is the process of converting an ore into its oxide by heating it strongly in absence or limited supply of air.
ZnCO_3(s) → ZnO_(s) + CO_2(g)

Question 15.
How is ‘cast iron’ different from ‘pig iron’ ?
Answer:
The iron obtained from blast furnace is called pig iron. It contains about 4% carbon and many other impurities (eg S, P, Si, Mn) in smaller amounts.

Cast iron, on the other hand, is made by melting pig iron with scrap iron and coke using hot air blast, it has slighly lower carbon content (about 3%) and is extremely hard and brittle.

Question 16.
Differentiate between “Minerals” and “Ores”.
Answer:
Compounds of metal that occur in nature are called minerals. Metals cannot be extracted economically from all types of minerals. Minerals which are used for the extraction of metals are known as ores.

Question 17.
Why copper matte is put in a silica-lined converter?
Answer:
Copper matte contains Cu₂S and FeS. Copper matte is heated with silica to remove the impurities of FeS as FeSiO₃ (slag).
2FeS + 3O₂ → 2FeO + 2SO₂
FeO + SiO₂ → FeSiO₃
Slag

Question 18.
What is the role of cryolite in the metallurgy of aluminium?
Answer:
Cryolite (Na₃AlF₆) makes alumina a good conductor of electricity and lowers the melting point of alumina from 2323 K to 1140 K.

Question 19.
How is leaching carried out in case of low-grade copper ores?
Answer:
The leaching of the low-grade copper ores is carried out with acids in the presence of air when copper goes into solution as Cu²⁺ ions. Thus,
2Cu + 2H₂SO₄ + O₂ → 2CUSO₄ + 2H₂O

Question 20.
Why is zinc not extracted from zinc oxide through reduction using CO?
Answer:
The standard free energy of formation (∆_rG°) of CO₂ from CO is higher than that of the formation of ZnO from Zn. Therefore, CO cannot be used to reduce ZnO to Zn.

Question 21.
The value of ∆_fG° for formation of Cr₂O₃ is -540 kJ mol^-1 and that of Al₂O₃ is -827 kj mol^-1. Is the reduction of Cr₂O₃ possible with A1 ?
Answer:

∆_rG° of the above reaction is -ve. Therefore Cr₂O₃ can be reduced by A1 to free chromium metal.

Question 22.
Out of C and CO, which is a better reducing agent for ZnO?
Answer:
The electrolytic reduction of metal chlorides like NaCl, KCl etc. gives chlorine as the by-product. When an aqueous solution of NaCl is electrolysed, H₂ is obtained at the cathode and Cl₂ at the anode.
NaCl → Na⁺ + Cl^–

At cathode:
2H₂O + 2e → H₂ + 2OH^–

At anode:
2Cl^– → Cl₂ + 2e

Question 23.
The choice of a reducing agent in a particular case depends on the thermodynamic factor. How far do you agree with this statement? Support your opinion with two examples.
Answer:
The thermodynamic factor helps us in choosing a suitable reducing agent for the reduction of a particular metal oxide to the metallic state as discussed below.

From the diagram, it is evident that metals for which the standard free energy of formation (∆_f G°)of their oxides is more negative can reduce those metal oxides for which the standard free energy of formation (∆_f G°)of their respective oxides is less negative. In other words. Any metal will reduce the oxides of other metals which lie above it in Ellingham diagram because the standard free energy change (∆_f G °) of the combined redox reaction will be negative by an amount equal to the difference in (∆_f G°) of the two-metal oxides. Thus, both Al and Zn can reduce FeO to Fe but Fe cannot reduce Al₂O₃ to Al and ZnO to Zn. Similarly, C can reduce ZnO to Zn but not CO.

Question 24.
Name the processes from which chlorine is obtained as a by-product. What will happen if an aqueous solution of NaCl is subjected to electrolysis?
Answer:
Sodium metal is prepared by Down’s process. It involves the electrolysis of a fused mixture of NaCl and CaCl₂ at 873 k

If however, an aqueous solution of NaCl is electrolysed, H₂ is evolved at the cathode while Cl₂ is obtained at anode. The reason being \(\mathrm{E}_{\mathrm{Na}^{+} / \mathrm{Na}}^{\circ}\), (-2.71) is much lower than \(\mathrm{E}_{\mathrm{H}_{2} \mathrm{O} / \mathrm{H}_{2}}^{\circ}\) (-0.832) and hence water is reduced to H₂ in preference to Na⁺ ions.

Question 25.
What is the role of a graphite rod in the electrometallurgy of aluminium?
Answer:
In the electrolytic reduction of alumina, graphite anode facilitates the reduction of Al₂O₃ to aluminium by electrolysis. Carbon reacts with oxygen liberated at anode producing CO and CO₂.

Question 26.
Outline the principles of refining of metals by the following methods:
(i) Zone refining
(ii) Electrolytic refining
(iii) Vapour phase refining.
Answer:
(i) Zone refining (Fractional crystallization): This method is used to prepare metals in an extremely pure state. Boron, gallium, indium, silicon, germanium etc. are purified by this method. This method is based on the fact that when molten impure metal is allowed to cool, the pure metal crystallizes out whereas the impurities remain behind in the melt.

Method: A thin bar of impure metal is taken. One zone of bar is heated with a moving circular heater in the atmosphere of inert gas. A narrow zone of the metal is melted. The pure metal crystallizes out of the melt while the impurities move into the adjacent molten zone.

The process is repeated several times till the impurities are completely driven to one end and the pure metal towards the other end. Then end of the rod where the impurities have collected is cut off. The metal obtained is extremely pure.

(ii) Electrolytic refining: This method is based upon the phenomenon of electrolysis. The crude metal is made anode whereas the thin sheet of pure metal is made the cathode.

An electrolyte is dissolved in the solution of some salt of the metal. On passing electricity the metal from the anode goes into the solution as ions due to oxidation while pure metal gets deposited at the cathode due to the reduction of metal ions. The less electropositive impurities settle down below the anode as anode mud.

(iii) Vapour phase refining: The crude metal is heated with a specific reagent to obtain a volatile compound at a lower temperature. The volatile compound is then heated at a higher temperature. The volatile compound decomposes at a higher temperature to give the metal Ni, Ti, Zr etc. are purified by this method.

(a) Mond process: Nickel is refined by this method. Impure nickel is heated in a current of CO at 330-350 K. Volatile nickel carbonyl Ni(CO)₄ is formed while the impurities remain behind. Nickel carbonyl is now heated to 450-470 K. It decomposes to give pure nickel.

(b) Van Arkel method: By this method, ultrapure metals are obtained. In this method, the metal is converted into a volatile unstable compound (e.g., iodide). The impurities remain behind. The unstable volatile compound is collected and it is then decomposed to get the pure metal. Titanium and Zirconium are purified by this method. These metals are used in space technology.

Question 27.
Predict conditions under which Al might be expected to reduce MgO.
Answer:
Above 1623K, Al can reduce MgO in Mg.

Al₂O₃ is more stable than MgO, hence Al reduces MgO above 1623K.

General Principles and Processes of Isolation of Elements Other Important Questions and Answers

General Principles and Processes of Isolation of Elements Objective Type Questions

Choose the correct answer :

Question 1.
Cryolite is mixed during the electrolysis of alumina because it:
(a) Decreases the m.p. of alumina
(b) Decreases electrical conductance
(c) Separates the impurity of alumina
(d) Decreases anode effect.

Question 2.
Which of the following metal is preserved by the film of its own oxide :
(a) Ag
(b) Fe
(c)Cu
(d) Al.

Question 3.
Which method is applicable for the extraction of Al from bauxite :
(a) Reduction by Mg
(b) Reduction by coke
(c) Electrolytic reduction
(d) Reduction by Fe.

Question 4.
The bauxite containing impurity of iron oxide is purified by :
(a) Hoop’s method
(b) Serpeck’s process
(c) Bayer’s process
(d) Electrolytic process.

Question 5.
Blister copper is:
(a) Ore of copper
(b) Alloy of copper
(c) Pure copper
(d) Copper containing 1% impurities.

Question 6.
In blast furnace iron oxide is reduced by :
(a) SiO₂
(b) CO
(c) C
(d) CaCO₃.

Question 7.
In the extraction of Fe from haematite, lime stone acts as :
(a) Reducing agent
(b) Slag
(c) Gangue
(d) Flux.

Question 8.
Cupellation is used in the metallurgy of:
(a) Cu
(b) Ag
(c) Al
(d) Fe

Question 9.
Which is the essential part of photographic plates and films :
(a) AgNO₃
(b)Ag₂S₂O₃
(c) AgBr
(d) Ag₂CO₃.

Question 10.
The compound obtained by the reaction of Zn with the excess of caustic soda :
(a) Zn(OH)₂
(b) ZnO
(c) Na₂ZnO₂
(d) ZnH₂.

Question 11.
Calomel is:
(a) Hg₂Cl₂
(b) HgCl₂
(c) Hg₂Cl₂ + Hg
(d) Hg + HgCl₂.

Question 12.
Is formed on adding potassium iodide solution in excess amount of mercuric iodide:
(a) Hg₂Cl₂
(b) K₂HgI₄
(c) Hg
(d) Hg + KI₃.

Question 13.
The colour obtained by the mixing of excess of KI in to HgCl₂ solution:
(a) Orange
(b) Brown
(c) Red
(d) Colourless.

Question 14.
Which metal does not form amalgum :
(a) Zn
(b) Cu
(c) Mg
(d) Fe.

Question 15.
Malachite is:
(a) Cu₂S
(b) CUCO₃.CU(OH)₂
(c) Cu₂O
(d) CuCO₃.

Question 16.
AgBr is soluble in hypo because its forms :
(a) Ag₂SO₃
(b) Ag₂S₂O₃
(c) [Ag(S₂O₃)]^–
(d) [Ag(S₂O₃)₂]^3-

Question 17.
AgCl is soluble in ammonia due to the formation of:
(a) [Ag(NH₃)₄]⁺
(b) [Ag(NH₃)₂]²⁺
(c) [Ag(NH₃)₄]³⁺
(d) [Ag(NH₃)₂]⁺.

Question 18.
When KI mixed with solution of CuSO₄, it form :
(a) Cul₂
(b) Cul^-2₂
(c) K₂[CUI₄]
(d) Cu₂I₂ + I₂.

Question 19.
When KCN reacts with solution of CuSO₄, it forms :
(a) CU(CN)₂
(b) CuCN
(c) K₂[Cu(CN)₄]
(d) K₃[Cu(CN)₄]

Question 20.
Na₂S₂O₃ used in photography as a :
(a) Reducing agent
(b) Developer
(c) Fixer
(d) Tonning agent.

Answers:
1. (a), 2. (d), 3. (c), 4. (c), 5. (d), 6. (b), 7. (d), 8. (b), 9. (c), 10. (c), 11. (a), 12. (b), 13. (c), 14. (d), 15. (b), 16. (c), 17. (d), 18. (d), 19. (d), 20. (c).

Question 2.
Fill in the blanks :

1. Malachite is an ore of ……………..
2. In stainless steel, along with iron …………….. and …………….. metals form alloys.
3. …………….. is used as a purgative.
4. Colloidal solution of …………….. is used as a medicine of eyes.
5. AgNO₃ is known as ……………..
6. Chemical formula of corrosive sublimate is ……………..
7. Froath floatation process is generally employed for …………….. ores.
8. The process in which metal oxide is reduced by A1 is known as ……………..
9. Is used for drying ammonia ……………..
10. …………….. is called lunar caustic.
11. The chemical formula of fluorspar is ……………..
12. Alkaline solution of HgCl₂ and KI is known as ……………..
13. Red hot steel is slowly cooled when it gets converted to soft steel, this is known as ……………..

Answers:

1. Cu
2. Cr, Ni
3. Calomel
4. Ag
5. Lunar caustic
6. HgCl₂
7. Sulphide
8. Alum- inothermic
9. CuO
10. Silver Nitrate
11. CaF₂
12. Nesseler’s reagent
13. Annealing.

Question 3.
Match the following :

I.

Answers:

1. (g)
2. (d)
3. (c)
4. (e)
5. (b)
6. (a)
7. (f).

II.

Answers:

1. (d)
2. (f)
3. (b)
4. (e)
5. (c)
6. (a).

III.

Answers:

1. (d)
2. (e)
3. (f)
4. (c)
5. (b)
6. (a).

Question 4.
Answer in one word / sentence :

1. The mixture of Cu₂S and FeS obtained from blast furnace is known as.
2. Which metal is purified by polling?
3. After developing which solution is used for the fixing of photographic films?
4. Chemical formula of philosophers’s wool is.
5. Chemical formula of horn silver.
6. Which compound is normally used for toning in photography?
7. Which are known as coinage metals?
8. Give the name of ore used for extraction of Cu.
9. Give the name of ore used for extraction of Iron.
10. What is the name of graph which is drawn between the absolute temperature and standard free energy change for formation of metal oxide?
11. What is the name of iron obtained after the removal of impurities from cast iron?
12. What is the method of slow cooling of hot hard steel known as?
13. What is the method of heating hard steel known as?
14. What iš the method of heating steel in pressure of ammonia known as?
15. What is Lunar Caustic?

Answers:

1. Matte
2. Copper
3. Hypo solution (Na₂S₂O₃)
4. ZnO
5. AgCl
6. Aurric chloride
7. Cu, Ag and Au
8. Copper pyrite
9. Haematite
10. Ellinghum diagram
11. Wrought iron
12. Annealing
13. Softening
14. Nitriding
15. AgNO₃.

General Principles and Processes of Isolation of Elements Very Short Answer Type Questions

Question 1.
Cryolite is added during the electrolysis of alumina to obtain aluminium. Give reason.
Answer:
Melting point of Alumina is very high (2050°C). By adding cryolite, melting point of alumina is lowered as well as electrolysis becomes easier.

Question 2.
When Al is placed in contact with cone. HNO₃, then no reaction seems to take place. Why ?
Answer:
Since, Al reacts with HNO₃ to form Al₂O₃ which forms a protective layer on the metal by which reaction do not proceed further.

Question 3.
Which compound of A1 is a good reducing agent ?
Answer:
Complex hydride Li[AlH₄] of Al is mainly a good reducing agent for organic compounds.

Question 4.
Write the chemical formula of the following :

1. Calomel
2. Lunar caustic
3. Philosopher’s wool
4. Corrosive sublimate.

Answer:

1. Calomel: Mercurous chloride (Hg₂Cl₂)
2. Lunar caustic : Silver nitrate (AgNO₃)
3. Philosopher’s wool: Zinc oxide (ZnO)
4. Corrosive sublimate : Mercuric chloride (HgCl₂).

Question 5.
Write the main ores of copper.
Answer:
Main ores of copper are as follows :
1. Oxide: Cuprite or Ruby copper (Cu₂O)
2. Carbonate:Azurite – 2CuCO₃.Cu(OH)₂
Malachite – CuCO₃.Cu(OH)₂ or CuCO₃.CuO.H₂O
3. Sulphide: Copper pyrites or Calcopyrite – Cu₂S + Fe₂S₃ or CuFeS₂
Copper glance or Calcocite – Cu₂S.

Question 6.
Give the chemical name, formula and two application of lunar caustic.
Answer:
Chemical name of lunar caustic : Silver nitrate (AgNO₃)
Applications : It is used for 1. Silvering of mirror. 2. Making marking inks and hair dyes.

General Principles and Processes of Isolation of Elements Short Answer Type Questions

Question 1.
Explain following process of steel:
(a) Annealing
(b) Hardening
(c) Tempering
(d) Nitriding.
Answer:
(a) Annealing: It is process of heating steel to redness followed by slow cooling due to this steel becomes soft and pliable.
(b) Hardening or Quenching: It is a process of heating steel to redness followed by sudden cooling by plunging the red hot steel into water or oil. Steel becomes brittle and hard.
(c) Tempering : It is a process of heating the hardened or quenched steel to a temperature much below redness (200-350°C) followed by slow cooling steel loses its brittleness completely or partially depending upon time and temperature.
(d) Nitriding : Formation of a layer of iron nitride by heating steel at 500-600°C in chamber of ammonia for 3-4 days is called nitriding. Steel becomes harder by this treatment.

Question 2.
Write method of preparation of copper sulphate (Blue vitriol) and its use.
Answer:
Method of preparation of copper sulphate :
1. By heating copper with dilute H₂SO₄ in the presence of air.
2Cu + 2H₂SO₄ + O₂ → 2CUSO₄ + 2H₂O

2. By the action of H₂SO4 on copper oxide, hydroxide or carbonate :
CuO + H₂SO₄ → CuSO₄ + H₂0
CU(OH)₂ + H₂SO₄ → CuSO₄ + 2H₂O
CuCO₃ + H₂SO₄ → CuSO₄ + H₂O + CO₂
Uses : (1) In dying and printing textile, (2) As a bacteriocidal, (3) As an insectiside, (4) In electrical cells.

Question 3.
Give the chemical reaction when CuSO₄ solution reacts with :
(i) NaOH solution
(ii) NH₄OH
(iii) KI solution
(iv) KCN.
Answer:
(i) It forms light blue precipitate of cuprichydroxide.
CuSO₄ + 2NaOH → Cu(OH)₂ + Na₂SO₄
(ii) It forms deep blue colour solution which is due to the formation of cupric ammonium sulphate complex.
CuSO₄ + NH₄OH → [CU(NH₃ )₄ ]SO₄ + 4H₂O
(iii) It liberates iodine.
CuSO₄ + 2 KI → K₂SO₄ + Cul₂
2CUI₂ → I₂ + Cu₂I₂
(iv) It forms potassium cupracyanide.

Question 4.
What is blue vitriol ? What is the effect of heat on it?
Answer:
Commercial name of blue vitriol is blue vitriol which contain five molecules of water of crystallization. ¡t is a blue coloured crystalline solid soluble in water.

Effect of heat : On heating 100°C it loses 4 molecules of water of crystallization. At 230°C, it loses 5^th molecules of water and becomes white amorphous powder. The white powder again becomes blue in presence of water. It undergoes dissociation on strong heating.

Question 5.
What are the main ores of Al ? How can impure aluminium ¡s purified?
Answer:
Main ores of Al:
I. Bauxite – Al₂O₃.2H₂O
2. Felspar – K₂O.Al₂O₃.6H₂O
3. Cryolite – Na₃AIF₆
Electrolytic refining of aluminium (Hoope’s electrolytic process): Aluminium is further purified by Hoope’s process. Process is carried out in an iron cell lined inside with carbon. The cell consist of three layers which differ in specific gravities. The lowest layer acting as anode consists of impure aluminium. A mixture of fluorides of Al, Ba and Na forms middle layer and acts as electrolyte. The uppermost layer is of pure aluminium and it acts as anode.

Following changes occur on passing electric current:

On electrolysis, aluminium ions of the electrolyte are discharged at cathode and pure aluminium collects as the uppermost layer. An equivalent amount of aluminium is taken up by the middle layer from the bottom layer. Thus, aluminium is transferred from bottom layer to the upper layer through the middle layer while impurities are left behind. Crude aluminium is added from time to time to continue the process. Thus 99-98% pure aluminium is obtained.

Question 6.
Differentiate between cast iron, wrought iron and steel.
Answer:
Differences between Cast Iron, Wrought Iron and Steel:

Question 7.
Give names and formula of any two ores of following metals :
(i) Al
(ii) Zn
(iii) Fe
(iv) Cu
(v) Ag.
Answer:

Question 8.
Write four different chemical reactions of copper with nitric acid. Give equations also.
Answer:
Chemical reaction of Cu with HNO₃:
(a) With cold and very dilute nitric acid, nitrogen gas is evolved.
5Cu + 12HNO₃ → 5CU(NO₃)₂ + 6H₂O + N₂

(b) With hot and dilute Nitric acid, nitrous oxide is obtained.
4CU + 10HNO₃ → 4CU(NO₃)₂ + N₂O + 5H₂O

(c) With 50% HN03, Nitric oxide is formed.
3Cu + 8HNO₃ → 3CU(NO₃)₂ + 2NO + 4H₂O

(d) With cone. HNO₃, Nitrogen peroxide is obtained.
CU + 4HNO₃ → CU(NO₃)₂ + 2NO₂ + 2H₂O.

Question 9.
Write the name of three alloys of copper and give the composition and one use of each.
Answer:
Alloys of copper, their composition and uses are given ahead :

Question 10.
Explain why a bulb placed in parallel series to the electrical circuit for extraction of Al from Al₂O₃ ?
Answer:
In the extraction of Al form Al₂O₃ by electrolysis. Al₂O₃ converted into Al with decrease in concentration of electrolyte bulb placed in parallel glass indicating that cell resistance has increased. Therefore, more alumina is added at this stage and carbon rods are also replaced.

Question 11.
Explain the purification of bauxite with chemical equations.
Answer:
Baeyer’s process applied for the purification of bauxite ore containing ferric oxide as chief impurity. This ore is usually red in colour and hence called red bauxite.

The powdered ore is roasted first to convert ferrous oxide. If any, to ferric oxide and then digested with a concentrated solution of sodium hydroxide under pressure at 150°C for several hours. Alumina dissolves in sodium hydroxide forming soluble sodium meta aluminate (NaAlO2) while ferric oxide and silica being insoluble settles down and are removed by filtration.

Sodium meta aluminate is then agitated with freshly precipitated Al(OH)₃ for 36 hours. As a result sodium meta aluminate gets hydrolysed forming precipitate of aluminium hydroxide.

The precipitate is washed, dried and ignited to get pure alumina while solution of NaOH is concentrated and used again.

Question 12.
Give equation for the Auto-reduction process of copper pyrite to obtain pure copper.
Answer:
Molten matte obtained by smelting is mixed with sand and taken in a Bessemer converter and air is blown through tuyers when FeS gets converted to FeO which reacts with SiO₂ to form slag (FeSiO₃) and some part of Cu₂S gets oxidized to Cu₂O.
2FeS + 3O₂ → 2FeO + 2SO₂
2FeO + 2SiO₂ → 2FeSiO₃
2Cu₂S + 3O₂ → 2Cu₂O + 2SO₂
Which reacts with the remaining Cu₂S and gets reduced to metallic copper. This is known as Auto-reduction.
2CU₂O + Cu₂S → 6Cu + SO₂

Question 13.
How many type of iron is found ? Give the name of each and two characteristics of each.
Answer:
Iron is of three types : 1. Cast Iron, 2. Wrought Iron, 3. Steel.
Characteristics 1. Cast Iron : (i) It consists of 2-5 to 4-5% carbon.
(ii) It is very hard and its melting point is 1200°C.

2. Wrought Iron : (i) It consists of 0-12 to 0-25% carbon.
(ii) It is soft and its melting point is 1500°C.

3. Steel: (i) It consists of 0-5 to 1 -5% carbon.
(ii) It is normally hard and melting point is nearly 1300°C.

Question 14.
Describe the purification method of bauxite having silica as impurity.
Answer:
Serpeck’s process : This process is used when bauxite ore contains consider-able amount of silica as impurity. In this process ore mixed with coke is heated to 1800°C in presence of nitrogen. Alumina gets converted into aluminium nitride, AIN.
Al₂O₃ + 3C + N₂ → 2 AIN + 3CO
Silica gets reduced to silicon which volatilises at this temperature.
SiO₂ + 2C → Si + 2CO
AIN is hydrolysed to aluminium hydroxide by water.
AIN + 3H₂O → Al(OH)₃ + NH₃
As usual aluminium hydroxide is converted into alumina.

General Principles and Processes of Isolation of Elements Long Answer Type Questions

Question 1.
Write note on photography.
Answer:
The process of producing an exact impression of an object on an art paper by using light is called photography.
Modern photography involves following steps :

(i) Preparation of sensitive plate or film : A paste of colloidal silver bromide or silver iodide in gelatin is the sensitive emulsion. It is prepared by adding ammonium silver nitrate solution to ammonium bromide solution containing gelatin.

This is allowed to stand in a warm room for sometime when silver bromide particle grow in size and at the sametime becomes more sensitive to light.

(ii) Exposure : The sensitive plate or film is mounted in a camera and exposed for a few second to the image of properly focussed object. The light reduces silver bromide to extremely small particles of silver.
2 AgBr → 2Ag + Br₂
Inverted image of the object which is formed on the plate is not visible and is therefore called latent image.

(iii) Developing : The exposed film or plate is immersed in a solution of developer. Developer is a weak reducing agent such as potassium ferrous oxalate or an alkaline solu-tion of organic reducing agents like pyrogallol or quinol.

When the plate dipped in developing bath, the parts affected by light are reduced to maximum extent while part not affected by light remain unattached by the developer.

The plate is therefore called negative plate.

(iv) Fixing : Sodium thiosulphate is used in fixing negative plates. Negative plate is washed and dipped in a hypo, it dissolves unaffected silver bromide and leaves metallic silver unchanged.

(v) Printing (Printing out paper or P.O.P.): Coated with silver chloride and silver citrate mixture. The process is slow and can be watched and controlled when the image of required shade is obtained, it is fixed and toned.

Question 2.
What is Blister copper ? Describe with labelled diagram of its purification by electrolysis.
Answer:
Copper is removed by inverting Bessemer converter. The metal thus obtained contains sufficient quantity of SO₂. On cooling, SO₂ comes out from the metal in the form of bubbles producing small blisters on the metal surface. The metal is 98% pure and is called Blister copper.

Purification of copper by electrolysis : Mixture of 15% CUSO₄ and 5% H₂SO₄ is taken in a big tank which is fitted with thick plates of copper which act as anode. Plates of pure copper act as cathode. On passing electric current the impure metal dissolves at anode and goes into solution and pure metal from solution starts depositing at cathode. The impurities of Pt, Au and Ag settle down as anode mud. The impurities of Ni, Fe, Zn remain in the solution. Metal of 99-99% purity is obtained by this method.

Question 3.
Explain Siemen-Martin open hearth process for the manufacture of steel.
Answer:
Siemen-Martin’s open hearth process : The mixture of cast iron (30 – 50%), scrap iron haematite (Fe₂O₃) and lime is melted in the open hearth furnace which has a basic or acidic lining depending upon impurities. Fe₂O₃ acts as oxidizing agent in the formation of steel and carbon gets oxidized to CO and escapes

Fe₂O₃ + 3C → 3CO + 2Fe
2Fe₂O₃ +3S → 4Fe + 3SO₂
10F₂2O₃ + 3P₄ → 20Fe + 6P₂O₅
2Fe₂O₃ + 3Si → 4Fe + 3SiO₂
Fe₂O₃ + 3Mn → 2Fe + 3MnO
Now steel containing required amount of carbon is obtained by addition of spiegel.

Advantages :

1. As the process proceeds slowly therefore, its control is easy.
2. Better quality of steel can be manufactured.
3. The composition and temperature can be easily controlled.
4. As no blast of air is passed therefore, very little steel is lost.
5. The steel can be directly obtained by the use of ore and scrap iron.

Question 4.
Write the names and formula of two ores of silver and describe the method of extraction of Ag from any ore.
Or
Write the names and formula of the two ores of silver and describe the cyanide method for the extraction of Ag.
Answer:
Two ores of silver: (i) Argentite or Silver glance – Ag₂S.
(ii) Horn silver or Silver chloride – AgCl.

Extraction of silver by cyanide process (Mac Arthur Forest Process):
Silver metal is extracted from the Argentite ore (Ag₂S) by cyanide process.
It is a modern process and based on the following principle :

1. Silver reacts with the cyanides of alkal metals and forms a soluble complex.
2. Impurities do not react with alkali cyanides.
3. More electropositive metals (like zinc and aluminium) displace silver from its complex cyanides.

The process involves the following steps :
1. Crushing and concentration: The ore is crushed and then finely powdered in ball mills. It is then subjected to the froath floatation process for concentration.

2. Treatment of the ore with sodium cyanide : The concentrated ore is treated with a dilute solution (about 0-5%) of sodium cyanide for several hours. The solution is continuously agitated by passing a current of air. Silver sulphide goes into the solution in the form of soluble complex.

The reaction is reversible. Hence, Na₂S must be removed so that the reaction may proceed in the forward direction.
The air blown in oxidizes the sulphide formed to thiosulphate and sulphate and thus enables the reaction to proceed in the forward direction.

3. Precipitation of silver : The above solution is filtered to remove insoluble impurities. It is then treated with zinc dust. Silver being less electropositive, gets displaced by more electropositive zinc and is precipitated.

Uses of silver glance :
(i) In silver plating on metallic articles e.g., tableware and silvering of mirrors
(ii) Used in medicine.

Question 5.
Explain the composition, uses of alloys of :
(i) Aluminium
(ii) Copper
(iii) Iron.
Answer:
Composition and uses of alloys of given elements :

Question 6.
Write the principle of extraction of copper from copper pyrite.
Or, Explain extraction of copper under the following heads :
(a) Smelting
(b) Bessemerization.
Answer:
Principle : Copper pyrite is mixed ore of copper and iron. As sulphur has got more affinity for copper. Therefore on heating the ore first iron oxide is formed which is removed completely and then sulphur is extracted.
Process involves following steps :
(i) Concentration : By froath floatation process, powdered ore is taken in tank containing water and palm or eucalyptus oil. Air stream is passed, sulphide ore form froth which can be removed and impurity settles down.

(ii) Roasting : Concentrated ore is heated in the presence of air in a reverberatory furnace, sulphide ore is converted into oxides.
2CuFeS₂ + O₂ → 2FeS + Cu₂S + SO₂
2Cu₂S + 3O₂ → 2CU₂O + 2SO₂
2FeS + 3O₂ → 2FeO + 2SO₂

(iii) Smelting : Roasted ore is mixed with coke sand and acidic flux and smelted in blast furnace of 15-20ft height following reaction takes place:
Cu₂O + FeS → Cu₂S + FeO
FeO + SiO₂ → FeSiO₃ (Slag)
flux slag
At last matte is obtained which is a mixture of cuprous sulphide and small quantity of ferrous sulphide.

(iv) Bessemerization : Matte is mixed with little sand and melted in oval shape Bessemer converter lined with CaO or MgO. Here cuprous sulphide first converted into cuprous oxide which on reduction (autoreduction) gives copper.
2FeS + 3O₂ → 2FeO + 2SO₂
FeO + SiO₂ → FeSiO₃(slag)
2Cu₂S + 3O₂ → 2Cu₂O + 2SO₂
Cu₂S + 2Cu₂O → 6Cu + SO₂

Metal obtained contains SO₂ on cooling SO₂ comes out from the metal in the form of bubbles producing blisters on the metal surface called blister copper.

(v) Purification (By electrolytic method) : Thin strip of pure copper is taken as cathode and thick strip of impure copper is taken as anode. CuSO₄ as electrolyte when electric current is passed pure copper get deposited at cathode.

Question 7.
What are the main ores of Zn ? Describe the vertical retort method for the extraction of Zn.
Or,
Describe the modern method for the extraction of Zn.
Answer:
Main ores of Zn:
(i) Zinc blende – ZnS
(ii) Calamine – ZnCO₃
(iii) Willemite – ZnSiO₄.
Extraction : Zinc is extracted from its ore by two methods :
1. Reduction process
2. Electrolytic process.

1. Reduction Process : It involves the following steps :
(i) Concentration : Zinc blende is concentrated by froath floatation process while calamine ore is concentrated by gravity separation process. Iron oxide if present in ore is removed by magnetic separation.
(ii) Roasting : Concentrated ore is heated at about 900°C in excess of oxygen. Zinc sulphide is oxidised to zinc oxide.
2ZnS + 3O₂ → 2ZnO + 2SO₂
A portion of ZnS is also oxidised to zinc sulphate but it decomposes at 900°C into ZnO
ZnS + 2O₂ → ZnSO₄
2ZnSO₄ → 2ZnO + 2SO₂ + O₂
In case of calamine ore, calcination is done instead of roasting.
ZnCO₃ → ZnO + CO₂
(iii) Reduction : Roasted or calcined ore is mixed with coke and heated to 1400°C. Ore gets reduced into the metal.
ZnO + C → Zn + CO.

Reduction can be done by the following method :

Vertical retort process : Process carried out in vertical retort is continuous. Vertical retorts are made up of highly refractory silicon carbide bricks capable of with standing high temperature. Heating is done externally using producer gas. A screw conveyer is provided in the extension at the bottom for the removal of ash. Just near the top an outlet is there. It is connected with condenser. Roasted ore and coke is fed into the retort through the charging door. Vapour of zinc along with CO passes into the condenser where zinc condenses while CO escaping out is used as fuel for heating the furnace. Zinc is removed periodically from the condenser.

Question 8.
What happens when (Give only equations):
(i) Blue vitriol is heated.
(ii) Ammonium hydroxide is added to silver nitrate solution.
(iii) Mercuric chloride is added to stannous chloride solution.
(iv) Copper reacts with hot and concentrated sulphuric acid.
(v) Mercuric chloride reacts with potassium iodide.
(vi) Silver nitrate reacts with hydrochloric acid.
(vii) AgNO₃ is heated.
Answers:

Question 9.
Explain with labelled diagram the method of electrolysis to obtain pure aluminium metal.
Answer:
Electrolysis of alumina (Hall-Heroult process) : Electrolysis of alumina is done in an iron tank fitted with a lining of gas carbon which acts as cathode. Graphite rods act as anode and a bulb is fitted in parallel as indicator for alumina content. The electrolyte is a mixture of alumina and cryolite (Na3AlF6). The melting point of alumina is very high (2050°C). But, in presence of cryolite (Na₃AlF₆) and fluorspar (CaF₂), it melts at 870°C. Then pure alumina is added to the tank which dissolves in cryolite mixture.

Reaction : Reactions take place as below :
Na₃AlF₆ → 3NaF + AlF₃
AlF₃ → Al+3 +3F^–
3F^– → 3e^– + 3F (oxidation) at anode
Al³⁺ + 3e^– → Al (reduction) at cathode
2Al₂O₃ +12F → 4AlF₃ + 3O₂ ↑
The reaction proceeds continuously. When amount of Al₂O₃ decreases resistance of electrolyte increases and the bulb in the parallel glows up. Therefore at this junction more alumina is added. The Al liberated at cathode collects at the bottom of the tank in molten state which is taken out through the exit. Coke is added to the mixture of cryolite and alumina which does not allow it to cool and further protects the eyes from light. 99% pure aluminium metal is obtained by this process.

MP Board Class 12th Chemistry Solutions

MP Board Class 12th General English Invitations and Replies

Formal and Informal Invitations

1. Formal Invitations प्रायः मुद्रित invitation cards होते हैं, जिनके द्वारा हम विवाह, जन्मदिन अथवा किसी शुभ कार्य में अपने परिचितों को निमन्त्रण पत्र भेजते हैं।
2. Informal Invitations अपने मित्रों व परिचितों को लिखे गये व्यक्तिगत पत्र की भाँति होते हैं।
3. दोनों प्रकार के Invitations में भाषा सरल होनी चाहिए।

Some Examples

Formal Invitations

1. You are a student of Govt. H. S. School, Ratlam. The school is holding its annual function. Write an invitation on behalf of the Principal of your school inviting the important persons of the town to attend the function to be held on August 17, 20……. at 10.00 am.
Answer:

The Principal and the Staff
of
Govt. H. S. School
Ratlam
request your benign presence – on the auspicious occasion
of
The Annual Function
of the school
at 10.00 am on August 17, 20…
Shri K. K. Agarwal, /. A. S.

will be the Chief Guest and will give away the prizes to the students.

R. S. V. P. :
Principal
Govt. H. S. School
Ratlam

2. Draft an invitation on behalf of Mr. and Mrs. Sharma of 21, Sector- 14, Bhopal, which they may use to invite their friends and relatives on the birth anniversary of their son Raunak at their residence on August 16, 20
Answer:

Mr. and Mrs. Sharma
request the pleasure of your benign presence
on the auspicious occasion of the
Birthday Celebrations
of
their son
Raunak
at their residence
21, Sector-14, Bhopal
at 3.30 p.m.
On
August 16, 20
R. S. V. P.
Mr. & Mrs. Sharma

Informal Invitations

1. Your friend from Manipur is staying in the school hostel. Send him an invitation to celebrate Diwali at your house.
Answer:
51, Ratanpura, Morena
25th, October 20….

Dear Mahesh
It gives me a great pleasure in inviting you to my house at Diwali. I am sure you will feel at home in the company of my younger brothers and sisters. We shall have great fun. I am sure you will join us in the ‘Puja’ and Diwali celebrations.

Yours sincerely
Manoj Saxena

2. You are Rishi Mishra of 24, Sector-21 .Chandigarh. Invite your class-fellow and friend on the wedding of your elder brother. (2011)

24, Sector-21
Chandigarh
20th March, 20….

Dear Sujeet
I invite you to be present at the wedding of my elder brother Ramesh on 21st of April, 20 Please join us at Lunch at 1 p. m. The marriage party will leave for Hotel Ranjeet, New Delhi exactly at 5 p. m. Kindly join us on the auspicious day and oblige.

Yours sincerely
Rishi Mishra

Replies

1. You are Pranjal. You have received a letter from your close friend, inviting you to attend the marriage of his sister. But unfortunately, you cannot attend it due to your previous commitments. Write him a letter regretting your inability to attend the marriage ceremony.
Answer:
201, Gautam Nagar, Bhopal
14th August, 20

Dear Ravi
I am indeed thankful to you for inviting me to attend the marriage of your elder sister Kalpana. Unfortunately, due to some unavoidable previous engagements, I shall not be able to attend it. Kindly accept a small wedding- gift that I am sending for Kalpana ‘Didi’ through a registered parcel on this auspicious occasion.

Yours sincerely
Pranjal

2. You are Prantik. You have been invited to attend a birthday party of your close friend. Respond to this invitation.
Answer:
15, L. I. G. Colony, Jabalpur
10th December, 20…………

Dear Harsh it
I feel honoured for being invited to attend your birthday party on 15th December, 20… . I am extremely sorry to inform you that some very urgent and unavoidable engagements will keep me tied down here on that day. Kindly accept a small gift that I am- sending by a registered parcel and oblige.

Wishing you a very happy birthday.
Yours sincerely
Prantik

Exercises For Practice

1. Write a suitable advertisement for Delhi Public School specializing in English speaking courses besides other courses.
2. On behalf of Kota classes, draft an advertisement to be published in a newspaper to attract the young students of IX, X, XI and XII who intend to become doctors.
3. In response to an appeal of the Prime Minister of India you have arranged a Charity Show in your school in aid of cancer patients of the country. Write out a notice to be displayed on the school notice- board informing the students about the show and seeking their co-operation for the success of the Charity Show.
4. You are Avinash Rao, Cultural Secretary of Golden Academy, Indore. Write a notice for the school notice-board informing the students that Inter-school Declamation Contest to be held in your school has been postponed for a week. Give details of the new program.
5. You are the Secretary of History Association of your school. -You are to organise an inter-school History Quiz in your school. Draft a notice/ circular inviting the entries from different schools of Delhi.
6. Draft a poster for your library on the ‘Value of Books and Reading’ in your life today. You may use a visual to make it meaningful.
7. You are the Secretary of the Creative Arts of your school. Your club is organising a ‘On-The-Spot Painting Competition’ at the school campus on the coming Sunday. Prepare a graceful poster for the occasion.
8. Design a poster for a ‘Science Exhibition’ you are going to organise in your school.
9. You are Raj Rishi Mehra of 24, M. P. Nagar, Bhopal. Draft an invitation for your friends and relatives, inviting them on the fifth birth anniversary of your daughter Neera at your residence.
10. Draft a. wedding invitation inviting guests, friends and relatives on
    the auspicious occasion of the’marriage of your son Mahesh with Meera, daughter of Sh. Ram Kishan on 8 September, 20
11. You are invited on the birthday celebrations of a friend, but you can’t be present there due to some unavoidable circumstances. Write a reply expressing your inability to attend the function.
12. Draft a reply, in not more than 50 words, accepting an invitation to be present on the occasion of the first marriage anniversary of your friend.

MP Board Class 12th English Solutions

MP Board Class 12th Biology Solutions Chapter 7 Evolution

Evolution NCERT Textbook Questions and Answers

Question 1.
Explain antibiotic resistance observed in bacteria in light of Darwinism selection theory.
Answer:
Darwinism theory of natural selection states that environment selects organisms with favourable variations and these organisms thus, survive and reproduce. It is observed when bacterial populations are exposed to certain antibiotic, the sensitive bacteria could not tolerate and hence, died due to the adverse environment. Whereas some bacteria that developed mutation became resistant to the particular antibiotic and survived. As a result such resistant bacteria survive and multiply quickly as compared to other sensitive bacteria. So, the whole population is regained by multiplication of resistant variety and antibiotic resis¬tant gene becomes widespread in the bacterial population.

Question 2.
Find out from newspapers and popular science articles any new fossil dis-coveries or controversies about evolution.
Answer:
Fossils of dinosaurs have revealed the evolution of reptiles in Jurassic period. As a result of this evolution of other animals such as birds and mammals has also been discovered. However, two unusual fossils recently unearthed in China have ignited a controversy over the evolution of birds confiiciusomis is one such genus of primitive birds that were crow sized and lived during the Cretaceous period in China.

Question 3.
Attempt giving a clear definition of the term species.
Answer:
Species is a morphologically distinct and reproductively isolated one or more natural populations of individuals which resemble one another closely and interbreed freely amongst themselves.

Question 4.
Try to trace the various components of human evolution (Hint: Brain size and function, skeletal structure, dietary preference, etc.)
Answer:
The various components of human evolution are as follows:

1. Brain capacity.
2. Posture
3. Food/Dietary preference and their important features.

Name brain capacity, posture, and food features:

• Dryopithecus Africans: Knuckle walker, walked similar to Gorillas and Chimpanzees (was more apelike) soft fruit and leaves; canines large, arm and legs are of equal size.
• Ramapithecus: Semi-erect (more manlike) seeds, nuts canines were small while molars were large.
• Australopithecus africanus: Australopithecus africanus 450 cm3 full erect posture, height (1 -05m) Herbivorous (ats fruits). Hunted with stone weapons, lived as trees, canines and incisors were small.
• Homo habilus: Homo habilus 735 cm3 fully erect posture, height (1 -5m) carnivo¬rous canines were small. They were first tool makers.
• Homo erectus: Homo erectus 800-1100 cm3 fully erect posture, height (1-5- l-8m) omnivorous. They used stone and bone tools for hunting games.
• Homo neanderihalensis: Homo neanderthalensis 1300 – 1600 cm3 fully erect posture, height (1-5 – l-6m) omnivorous cave dwellers, used hiles to protect their bodies and buried their dead.
• Homo sapiens fossils: Homo sapiens fossils 1650 cm3 fully erect posture with height (l -8m) omnivorous. They had a strong jaw with teeth close together. They were cave dwellers, made painting and carvings in the caves. They developed a culture and were called first modem man.
• Homo sapiens sapiens : Homo sapiens sapiens 1200 – 1600 cm3 fully erect pos¬ture, height (1-5 – l-8m) omnivorous. They are the living modem men with high intelligence. They developed art, culture, language, speech, etc. They cultivated crops and domes¬ticated animals.

Question 5.
Find out through the internet and popular science articles whether animals other than man have self-consciousness.
Answer:
There are many animals other than humans, which have self-consciousness. An example of an animal being self-conscious is dolphins. They are highly intelligent. They have a sense of self and, they also recognize others among themselves and others. They communicate with each other by whistles, tail-slapping, and other body movements, not dolphins, there are certain other animals such as Crow, Parrot, chimpanzees, Gorilla, Orangutan, etc., which exhibit self-consciousness.

Question 6.
List 10 modern-day animals and using the internet resources link them to a corresponding ancient fossil. Name both.
Answer:
Modern and Ancient corresponding animals :

Question 7.
Practice drawing various animals and plants.
Answer:

Question 8.
Describe one example of adaptive radiation.
Answer:
Darwin’s finches in the Galapagos Island once had a common ancestor but with evolution, they modified into different types according to their food habitat.

Question 9.
Can we call human evolution adaptive evolution?
Answer:
No, because parent species of homosapiens have evolved by progressive evolution
(Homo habilis —Homoerectus lineage)

Question 10.
Using various resources such as your school library or the internet and discussions with your teacher, trace the evolutionary stages of any one animal, say horse.
Answer:
The evolution of horse started with Eohippus during the Eocene period. It involved the following evolutionary stages :

• Gradual increase in body size
• Elongation of head and neck region
• Increase in the length of limbs and feet
• Gradual reduction of lateral digits
• Enlargement of third functional toe
• Strengthening of the back
• Development of brain and sensory organs
• Increase in the complexity of teeth for feeding on grass

• Eohippus: It had a short head and neck. It had four functional toes and a splint of 1 and 5 on each hind limb and a splint of 1 and 3 on each forelimb. The molars were short crowned that were adapted for grinding the plant diet.
• Mesohippus: It was slightly taller than Eohippus. It had three toes in each foot.
• Merychippus: It had the size of approximately 100 cm. Although it still had three toes in each foot, it could run on one toe. The side toe did not touch the ground. The molars were adapted for chewing the grass.
• Pliohippus: It resembled the modern horse and was around 108 cm tall. It had a single functional toe with a splint of 2nd and 4th in each limb.

Equus: Pliohippus gave rise to Equus or the modern horse with one toe in each foot. They have incisors for cutting grass and molars for grinding food.

Evolution Other Important Questions and Answers

Evolution Objective Type Questions

1. Choose the Correct Answer.

Question 1.
These are found in the atmosphere of earth before evolution:
(a) Water vapour, CH₄, NH₃ and Oxygen
(b) CO₂, NH₃, H₂ and Water vapour
(c) CH₄, NH₃, H₂ and Water vapour
(d) CH₄, O₃, O₂ and Water vapour.
Answer:
(c) CH₄, NH₃, H₂ and Water vapour

Question 2.
Which gas is absent in the atmosphere of the earth at the time of origin of the earth:
(a) NH₃
(b) H₂
(c) O₃
(d) CH₄
Answer:
(c) O₃

Question 3.
Which gaseous mixture are used and found the amino acid by Miller:
(a) Methane, Ammonia, Hydrogen and Water vapour
(b) Methane, Ammonia, Nitrogen and Water vapour
(c) Methane, Nitrogen, Hydrogen and Water vapour
(d) Ammonia, Carbon dioxide, Nitrogen and Water vapour.
Answer:
(a) Methane, Ammonia, Hydrogen and Water vapour

Question 4.
Who gave the theory “Survival of the fittest” :
(a) Charles Darwin
(b) Herbert Spencer
(c) Lamarck
(d) Hugo de Vries.
Answer:
(b) Herbert Spencer

Question 5.
Who gave the theory of inheritance of acquired, characters :
(a) Charles Darwin
(b) Lamarck
(c) Valles
(d) de Vries.
Answer:
(b) Lamarck

Question 6.
Who wrote origin of species:
(a) Oparin
(b) Beajman
(c) Lamarck
(d) Darwin.
Answer:
(d) Darwin.

Question 7.
What is the name of Darwin’s ship:
(a) Gangotri
(b) Beagle
(c) Atlantic
(d) Seagull.
Answer:
(b) Beagle

Question 8.
‘Atmosphere is a factor of variation’ who gave this theory :
(a) Mendel
(b) Darwin
(c) Lamarck
(d) Laplace.
Answer:
(c) Lamarck

Question 9.
Darwinism explains it:
(a) Characters are grown by heredity
(b) Species are changed into structural form with time.
(c) Nature selected the animals which are adapted
(d) Origin of evolution due to effect of environment.
Answer:
(c) Nature selected the animals which are adapted

Question 10.
Which antibiotic is used to Replica planting experiment of Ladderberg:
(a) Penicillin
(b) Streptomycin
(c) Erythromycin
(d) Neomycin.
Answer:
(a) Penicillin

Question 11.
Which is the basic unit of natural selection:
(a) Species
(b) Community
(c) Genous
(d) Solitary organism.
Answer:
(c) Genous

Question 12.
Who gave the theory of natural selection :
(a) Lamarck
(b) de Vries
(c) Darwin
(d) Mendel.
Answer:
(d) Mendel.

Question 13.
Darwinism is based on:
(a) Segregation
(b) Independent assortment
(c) Quantitative heredity
(d) Natural selection.
Answer:
(b) Independent assortment

Question 14.
Who discover the uses and experiment of organs:
(a) Valles
(b) Lamarck
(c) Darwin
(d) de Vries
Answer:
(a) Valles

Question 15.
The unit of natural selection :
(a) Solitary animal
(b) Family
(c) Community
(d) Species.
Answer:
(d) Species.

Question 16.
Mule is a product of:
(a) Mutation
(b) Reproduction
(c) Inter-species hybridization
(d) Intra-species hybridization
Answer:
(b) Reproduction

Question 17.
Who use first the word ‘species’:
(a) Linnaeus
(b) John
(c) Aristotle
(d) Darwin
Answer:
(b) John

Question 18.
Homologus organs are :
(a) Similar in origin
(b) Similar in function
(c) Similar in evolution
(d) Similar in behaviour.
Answer:
(a) Similar in origin

Question 19.
Which era are called as the golden period of Reptilia or Dinosaurs:
(a) Mesozoic
(b) Cenozoic
(c) Palaeozoic
(d) Cenozoic.
Answer:
(a) Mesozoic

Question 20.
Dinosaurs are distinct in this era:
(a) Jurassic
(b) Triassic
(c) Cretaceous
(d) Permian.
Answer:
(c) Cretaceous

Question 21.
Vestigial organs of human’ are:
(a) Wisdom teeth, Coccyx, Nail, Eyelids, Vermiform appendix
(b) Wisdom teeth, Coccyx, Vermiform appendix, Pancreas
(c) Wisdom teeth, Coccyx, Vermiform appendix, Nictating membrane
(d) Coccyx, Wisdom teeth, Nail, Auricular muscle.
Answer:
(c) Wisdom teeth, Coccyx, Vermiform appendix, Nictating membrane

Question 22.
How made fossils:
(a) Animals are naturally buried inland after death
(b) Animals are decomposed by decomposers
(c) Animals are eaten by their hunter species
(d) Animals are destroyed due to environmental conditions.
Answer:
(d) Animals are destroyed due to environmental conditions.

Question 23.
Species which are similar in shape and different in reproduction are called :
(a) Sub-species
(b) Sibling
(c) Isotopic
(d) Allopatric species.
Answer:
(c) Isotopic

Question 24.
Name the ship which had been used by Darwin for the journey:
(a) Ciloge
(b) Beagle
(c) Seagull
(d) Atlantic.
Answer:
(b) Beagle

Question 25.
Life is not in this era :
(a) Mesozoic
(b) Palaeozoic
(c) Cenozoic
(d) Azoic.
Answer:
(d) Azoic.

Question 26.
Which factor is responsible for evolution due to New-Darwinism theory:
(a) Mutation
(b) Useful variation
(c) Hybridization
(d) Mutation and Natural selection.
Answer:
(d) Mutation and Natural selection.

Question 27.
Found the age of fossils by which :
(a) By quantity of calcium ions
(b) By quantity of organic radioactive components
(c) By struggle from other mammals
(d) By the structure of bones.
Answer:
(d) By the structure of bones.

Question 28.
Darwin finches are related to which of the following evidence:
(a) Fossils
(b) Embryology
(c) Anatomy
(d) Geographical distribution.
Answer:
(d) Geographical distribution.

Question 29.
Who gave Recapitulation theory :
(a)Weizmann
(b) Haeckel
(c) Darwin
(d) Malthus.
Answer:
(b) Haeckel

Question 30.
Which definition of organic evolution is correct:
(a) Evolutionary history of a species
(b) History of species with the variations in the species
(c) Embryonal history of species
(d) Development of species.
Answer:
(a) Evolutionary history of a species

Question 31.
What is the perfect sequence of development of human:
(a) Peking man, Heidelberg man, Neanderthal Cro-Magnon
(b) Peking man, Homo sapiens, Cro-Magnon, Neanderthal
(c) Peking man, Neanderthal,.Homo sapiens, Heidelberg
(d) Peking man, Cro-Magnon, Homo sapiens, Neanderthal.
Answer:
(a) Peking man, Heidelberg man, Neanderthal Cro-Magnon

Question 32.
Which of the following is the most primitive ancestor of man :
(a.) Australopithecus
(b) Ramapithecus
(c) Homo habilis
(d) Homo neanderthalensis.
Answer:
(b) Ramapithecus

Question 33.
Ancestral amphibians were tetrapods that evolved during :
(a) Jurassic period
(b) Cretaceous period
(c) Devonian period
(d) Carboniferous period.
Answer:
(c) Devonian period

2. Fill in the Blanks:

1. Earth is a member of …………….
2. ……………. wrote ‘Origin of life’.
3. Oxygen is found on the earth because photo-synthetic organisms are present on the earth, this phenomenon is called …………….
4. ………….. is the connecting link between Reptiles and Aves.
5. …………………. is the ancesters of horse.
6. The evolution of ……………. molecule set the stage for the evolution of autotrophs.
7. Evolution of birds and mammals were ……………. era.
8. Golden era of Dinosaurs is ……………. period.
9. ……………. fossil man has been known from Shivalik hills in India.
10. Book of Charles Darwin “Origin of life” has been explained of …………….
11. ……………. be change of hareditary characters.

Answer:

1. Solar system
2. Oparin
3. Oxygen revolution
4. Archaeopteryx
5. Eohippus
6. Chlorophyll
7. Jurassic
8. Mesozoic
9. Ramapithecus
10. Natural selection
11. Mutation.

Question 3.
Match the Following :

Answer:

1. (d)
2. (a)
3. (e)
4. (c)
5. (b)

Answer:

1. (d)
2. (c)
3. (e)
4. (a)
5. (b)
6. (f).

4. Answer in One Word / Sentence:

1. The matter which gave rise to the universe 15 billion years ago.
2. The matter is a link between acellular and cellular systems.
3. The island at which Darwin studies the organisms for his theory of evolution.
4. Origin of two or more unlike species from a common ancestor.
5. The whole process of development at changes from embryo to adult organism.
6. The process of changes in the course of origin of a new species.
7. The theory of organic evolution proposed by Darwin.
8. The permanent, heritable, and spontaneous changes in organisms.
9. The remains of ancient organisms.
10. The organs which are different in their origin but have a similar function.

Answer:

1. Ylem
2. Coacervates
3. Galapagos
4. Adaptive radiation
5. Ontogeny
6. Phytogeny
7. Natural selection
8. Mutation
9. Fossils
10. Homologous organs.

Evolution Very Short Answer Type Questions

Question 1.
What is abiogenesis?
Answer:
It is the process of the appearance of the first form of life slowly from non-living molecules.

Question 2.
Name the theory which tells about the milky way and the formation of a star.
Answer:
Big Bang.

Question 3.
What is evolutionary biology?
Answer:
Science deals with the study of the history of life forms on earth.

Question 4.
Which planet has the possibility of the origin of life other than earth?
Answer:
ars.

Question 5.
Define homologous organs.
Answer:
The organs have similar embryonic origin but they perform different functions.

Question 6.
What is the art of limitation, which is practiced the world over from annoying siblings or plant resembles another creature to gain other advantages?
Answer:
Mimicry.

Question 7.
Define homology.
Answer:
Homology refers to the similarities in the fundamental anatomy and embryology of organs of different groups of plants and animals.

Question 8.
What is the collection of different genes within an interbreeding population?
Answer:
Gene pool.

Question 9.
What is the analogy?
Answer:
It refers to structurally different organs evolving for the same function in a different groups of plants and animals.

Question 10.
Who proposed the theory of natural selection?
Answer:
Darwin.

Question 11.
Why are the wings of a butterfly and of a bat called analogous? (CBSE 1996, 2009)
Answer:
They are of different embryonic origin but similar function.

Question 12.
The astronomical distance measured in?
Answer:
The astronomical distance measured in Light years.

Question 13.
Give 2 examples of evolution due to anthropogenic activities.
Answer:
DDT resistance in mosquitoes and Antibiotic resistance in microbes.

Question 14.
What is a fossil?
Answer:
Fossils are the remains or impressions of ancient organisms preserved in sedimentary rocks or other media.

Question 15.
Name the fossil animal which serves as a connecting link believers reptiles and birds. (CBSE 1995)
Answer:
Archaeopteryx – fossil bird.

Question 16.
Name the scientist who tells the spontaneous theory is wrong.
Answer:
Louis Pasteur’s.

Question 17.
Name the placental mammal corresponding to the Austrian “Spotted cuscus” and Tasmanian “tiger cat”. Which have evolved as a result of convergent evolution (CBSE 2008)
Answer:
Lemur and Bobcat.

Question 18.
In which ship Darwin studied nature?
Answer:
Beagle.

Question 19.
Name any two vertebrates’ body organs which are homologus organs of the human forelimb.
Answer:

1. Flipper of Whale
2. Wing of birds

Question 20.
What is the scientific name of modern man?
Answer:
Homo sapiens.

Question 21.
What is meant by gene pool?
Answer:
The sum total of all the genes pooled by the members of a population.

Question 22.
Who are the early human and sub-human?
Answer:
Ramapithecus is early human and Australopithecus is early human.

Question 23.
Name the immediate ancestor of lycopods.
Answer:
Zosterophyllum.

Question 24.
Which type of human was ‘Cro-Magnon’ on the basis of food intake?
Answer:
Cro-Magnon was carnivorous.

Question 25.
Darwin’s theory is known as the “Theory of Natural selection”. How is Lamark’s theory know? (CBSE 1995)
Answer:
Theory of inheritance of acquired characters.

Question 26.
Give the name of apelike ancestors of humans
Answer:
Apelike ancestors of humans are Dryopithecus.

Question 27.
Define genetic drift.
Answer:
Random changes in the allelic frequencies of a population, occurring only by chance events, constitute genetic drift.

Evolution Short Answer Type Questions

Question 1.
Describe the theory of abiogenesis.
Answer:
According to this theory, the first form of life arose slowly through evolutionary forces from non-living molecules.

• The reducing atmosphere and high temperature favoured the formation of diverse organic compounds from inorganic molecules.
• Then the first non-cellular forms of life i.e. self duplicating molecules like RNA evolved.

Question 2.
What is oxygen revolution? Explain.
Answer:
Oxygen revolution: Evolution of 02 in photosynthesis during primitive environmental conditions is very important because, it is required in the evolution of organism and conversion of reducing environment into oxidizing environment hence, it is called oxygen revolutioa Oxygen evolution should cause the following changes in the environment:

• Oxygen evolution should cause the conversion of reducing environment into oxidizing environment
• Ozone layer is formed 15 miles above from the earth which absorbs the ultraviolet light of the sunlight and thus, prevents the entry of uv light in the atmosphere.
• O₂ present in the environment dissociates methane (CH₄) into CO₂ and O₂. This CO₂ is used in photosynthesis.
• NH₃ of the primitive environment is dissociated into H₂O.and nitrogen.
  CH₄ + 2O₂2 → CO₂ + 2H₂O
  4NH₃ + 3O₂ → 2N₂ + 6H₂O.

Question 3.
Amongst pea tendrils, opuntia spines, lemon thorns and cucurbit tendrils. Which ones are homologous structures? Why do you call them homologous? (CBSE 1999)
Answer:

• Pea tendrils and opuntia spines are homologous.
• Lemon thorm and cucurbit tendrils are homologous.

Reason:

• Pea tendrils and Opuntia spines are modified leaves (same orign) but perform different functions.
• Lemon thorns and cucurbit tendrils are modified stems. Both arise from axillary positions. Both perform different functions.

Question 4.
Mention the names of discoveries and principles given by the following scientists:

1. Louis Pasteur
2. A. I. Oparin
3. Urey and Miller
4. Francesco Redi
5. Faux.

Answer:

1. Louis Pasteur: He proved that air contains spores of microorganisms and the Biogenesis theory was supported by him.
2. A. I. Oparin: He presented the biochemical explanation of the origin of life in his book “The Origin of Life on Earth”.
3. Urey and Miller: They supported the evidence of the Oparin-Haldane theory of Origin of life.
4. Francesco Redi: He by conducting experiments proved that abiogenesis cannot exist but biogenesis theory can exist i.e., Life arises from pre-existing life.
5. Faux: He has been experimentally supporting the organic substances as described by Oparin.

Question 5.
Write down the difference between:

1. Ozone and Oxygen
2. Micro-molecules and Macro-molecules.

Answer:
1. Differences between Ozone and Oxygen :

2. Differences between Micro-molecules and Macro-molecules :

Question 6.
What are homologous organs?
Or
What is homology?
Answer:
Organs which are similar in structure and origin but different in appearance and functions are called homologous organs and the phenomenon is called homology.
Examples: Forelimbs of bat, wings of bat, hands of man, forelimbs of horse. These are examples of homologous organs because, they are made up of similar bones, hu¬merus, radius-ulna, carpals, metacarpals and fingers.

Question 7.
How do Darwin’s finches illustrate adaptive radiation? (AI2008)
Answer:
Darwin finches are varieties of small blackbirds found in the Galapagos Islands. They all must have evolved on the island itself. From the original seed-eating birds, many other forms evolved, with altered beaks enabling them to become insectivorous and vulgarian habits. This process of evolution of different species in the same geographical area starting with one species and radiated to other areas is called adaptive radiation.

Question 8.
What is the difference between homologous and analogous organs? Give two examples of each of them.
Answer:
Differences between Homologous and Analogous organs :

Question 9.
State Hardy – Wein berg principle of genetic equilibrium knowing that genetic drift disturbs this equilibrium. Mention what does this disturbance in genetic equilibrium leads to?
Answer:
Hardy Weinberg’s principle states that allele frequencies in a population are stable and remain constant from generation to generation.

• Genetic drift refers to a change in allele frequencies of a population acquiring by chance.
• Such a change in allele frequency may be so different that the population becomes a different species.
• The original drifted population is called founder and the effect is called the founder effect.

Question 10.
What is connecting link? Also, explain the significance of connecting links.
Answer:
Connecting link: Certain organisms which share characters with two different groups. Such organisms are called connecting links.
Examples: Some fossils present in nature like Archaeopteryx is known as fossils connecting link and it is the connecting link of birds and reptiles. Neopilina, Platypus, Protopterus, etc. Neopilina is a mollusk and is the connecting link of Mollusca and Annelida.
Significance of Connecting links: It proves the process of organic evolution and helps in the identification of organisms closely related.

Question 11.
Write down the demerits of Darwinism.
Answer:
Some of the demerits of Darwinism are:

• Darwinism stresses upon small fluctuating variations which has no role in evolution.
• Does not satisfactorily explain effect of use and disused and presence of vestigial organs:
• It did not differentiate somatic and germinal variations.
• It explains survival of the fittest but not arrival of the fittest. .

Question 12.
Differentiate between Lamarckism and Darwinism.
Answer:
Differences between Lamarckism and Darwinism:

Question 13.
Explain Lamarckism in short
Or
Explain Lamarckism of organic evolution in brief.
Answer:
Lamarckism: In 1809, Lamarck has proposed a theory to explain organic evolution, which is known, as the “Theory of inheritance of acquired characters.” According to Lamarck, organisms acquire certain characters during their lifetime due to changes in the environment and these acquired characters are heritable. According to this theory, new species are originated as follows:

• New requirements and wills are produced in the organisms due to the effect of changing environment
• New requirements and wills of organisms resulting in the production of new habits.
• Changes in the habit bringing about modifications of the organ.
• New habits resulting in the use or disuse of the organs:
• Use of organ resulting in the development of acquired characters.
• These acquired characters are heritable.
• Inheritance of acquired characters resulting in the development of new species.

Evolution Long Answer Type Questions

Question 1.
Draw a well-labelled diagram of Miller and Urey’s experiment
Answer:

Experimental evidence of Chemical evolution or Miller’s experiment:

• Experiment was performed by S.L. Miller and H.C. Urey in 1953.
• Experimental set-up: In a closed flask containing CH4, H2, NH3 and water vapoiy at 800°C, electric discharge was create. The conditions were similar to those in primitfve atmosphere.
• Observations: After a week, they observed presence of amino acids and complex molecules like sugars, nitrogen bases, pigments and fats in the flask.
• Conclusions : (i) It provides experimental evidence for the theory of chemical origin.
  (ii) It showed that the first non-cellular form of life was created about 3 billion years ago.
  (iii) It showed that non-cellular biomolecules exist in the form of DNA, RNA, polysaccharides and protein.

Question 2.
Write an essay on modern concepts of origin of life.
Or
Explain the role of non-living in origin of life.
Answer:
Modern concept of origin of life : The modem concept of origin of life was postulated by a Russian biochemist A.I. Oparin in 1936. According to this theory, after the formation of earth various chemicals played important role in the formation of atmosphere. Life originated and first organism came into existence from certain molecules when atmospheric conditions became suitable. According to Oparin, life originated in the following steps:

1. Formation of earth and its atmosphere: Earth is believed to be originated some 4,500 million years ago by the condensation and cooling of the clouds of cosmic dust and gases called ylem. The heavier elements collected at the core and lighter elements around the core. Outermost layer contains H, C, O and N. Oxygen was found only in combination of other elements. These four elements reacted with each other forming H₂, H₂O, CH₄, NH₃, CO₂ and HCN.

2. Formation of small organic molecules: The mixture of methane, ammonia, water and hydrogen comes in contact of solar energy. Cosmic rays and electric discharge could produce some simple organic compounds. These simple organic compounds formed in such a way and accumulated in primitive atmosphere and oceans were responsible for synthesis of complex micro molecules as follows :

3. Formation of polymers : It is clearly understood from the above description that a large number of micro molecules such as hydrocarbons, amino acids, fatty acids, purine and pyrimidines and simple sugars accumulated in the oceans. When atmospheric water condensed on further cooling, the inorganic precursors collided, reacted and aggregated to form new molecules of increasing size and complexity. Thus, by polymerization macromolecules were formed. The chemical reactions for the formation of macromolecules can be summarized as follows:

• Sugar + Sugar → Polysaccharides
• Fatty acid + Glycerine → Lipids
• Amino acid + Amino acid → Protein
• Nitrogenous base (Adenine) + Sugar + Phosphate → Adenosine phosphate
• Nitrogenous base + Sugar → Nucleoside
• Nucleoside + Phosphate → Nucleotide
• Nucleotide + Nucleotide → Nucleic acid.

4. Formation of molecular aggregates and primitive cells: Over a vast of time, these molecules became associated with one temporary complex. Ultimately, it leads to the formation of a coacervate. A coacervate is a solution of high molecular weight of chemicals, i.e., proteins and carbohydrates, which become bounded by lipid membrane, which is selectively permeable. The coacervate grows by absorbing molecules from its environment. The substances which got accumulated in the coacervates underwent reactions and resulted in the molecular reorganization of some proteins into enzymes. A coacervate having nucleoprotein surrounded by various nutritive organic substances and covered by surface membrane is considered to be the precell, which got later transformed into first living cell. The coacervate can reproduce by budding.

5. Evolution of complex biochemical reactions: Primitive organism utilize chemi¬cal substances present in the environment as food hence, they are:

• Heterotrophic, chemosynthetic organisms appeared due to mutation and natural selection in heterotrophs.
• Blue-green algae evolved from chemosynthetic organisms by mutation and natural selection.
• The liberation of free oxygen into the atmosphere produced by the blue-green algae due to the process of photosynthesis.

It finally changed the reducing atmosphere into an oxidizing one and therefore, all possibilities of further chemical evolution were finished.
Free-living eukaryotes originated in the ocean from blue-green algae.

6. The origin of well-developed organisms: From the simple eukaryotes which were like unicellular organisms of today various forms of life evolved during the passage of time.

Question 3.
Write the process of formation of organic molecules in seawater on earth with the help of Miller and Urey’s experiment
Answer:
The work of A.I. Oparin (1938-1965), HLUrey, and Stanley Miller (1959) provided evidence in the favour of biochemical origin of life. They had prepared the atmos¬phere like that of primitive earth and as described by Oparin, they made the synthesis of organic compounds by the following methods:

(i) Four elements H, C, O (not free O₂), and N react .with each other to form H₂O, CH₄, NH₃, CO_2, and HCN on the primitive earth.

(ii) From these four elements following organic molecules were formed in seawater of earth:
(a)

(b) CH₄, H₂O, NH₃ → Amino acids.
(c) CH₄, HCN, H₂O, NH₃ → Nitrogenous bases.

(iii) Macro-molecules of organic compounds were synthesized by these above pre¬pared organic compounds.

• Sugar + Sugar → Polysaccharides (Carbohydrate).
• Fatty acids + Glycerol → Fats.
• Amino acid + Amino acid → Protein.
• Nitrogenous base + Sugar → Nucleoside.
• Nucleoside + Phosphoric acid → Nucleotide.
• Nucleotide + nucleotide → Nucleic acid.
• Nitrogenous base (Adenine) + Sugar + Phosphate →Adenosine phosphate.

(iv) The above organic compounds and salts together constituted the first living being.

Question 4.
Name connecting link of reptiles and birds. Also, write their characters.
Answer:
Archaeopteryx is the connecting link between birds and reptiles. Archaeopteryx was a bird. It is regarded as the connecting link between reptiles and birds, which suggests the path of evolution of the latter from the former. It is found as fossils. They are found during the Jurassic period for 140 million years. Archaeopteryx exhibits both reptiles and birds like characters.

1. Reptiles like characters:

• Bones were similar to that of reptiles in which air sacs were absent.
• Tail-bearing vertebra.
• It had teeth in jaws, scales were present on the body.
• Metacarpals were free.
• The pelvic girdle recombines with the pelvic girdle of reptiles.

2. Birds like characters:

• Presence of feathers on the body.
• Forelimbs were modified in wings.
• Skull large and monocondylar.
• Jaws were modified into a beak.
• Hallux was backward and pointed.

Question 4.
(i) The study of fossils support evolution of organism. Discuss?
(ii) Describe convergent evolution with an example each from animals and plants.
Answer:
(i) By the careful analyses of the distribution of fossils in the different strata of rocks gives the time of the history of the earth the study showed that life form varied over time, some were simple and those in the superfluid layers resembled modern organism. Some fossils indicate connecting links i.e. they share features of two groups of organisms indicating the evolution of one group into the other.

(ii) Convergent evolution refers to the evolutionary process of selection of similar adaptive features in different groups of organisms in a similar habitat towards the same function.

• It is the similar habilat that has resulted in selection of similar structures.
• Analogous structures that are not anatomically similar but perform the same functions result from convergent evolution. Examples: Wings of butterfly and wings of birds.

Question 6.
Organic Evolution is a continued process, explain it in favour of it giving any three evidences.
Answer:

Evolution is a complex phenomenon accounting for the present-day diversity among organisms. But it has clearly maintained the basic unity among them since it occurred over a period of millions of years, no one would have seen/recorded evolution and hence scientists have provided various evidence to prove evolution.

Some of the evidence of organic evolution are described below :

I. Evidences from Embryology :

• Important activities that occur various animals are:
• For survival, all animals get energy and various substances from the environment.
• In all organisms, energy is produced from ATP.
• In all organisms, the duplication of DNA is similar.
• In all organisms, protein synthesis is the same and it is produced from ribosomes.
• In all organisms respiration and steps of respiration is the same.
• All organisms multiplicate and reproduce, due to which they have basic similarities.
• All organisms conduct hereditary characters on similar principles.

II. Evidence from Anatomy: The anatomy of living organisms will be explained with different examples:

• Homologous organs: Organs which are similar in structure and origin but different in function and appearance is known as homologous organs.
• Analogous organs: Organs which are different in origin and structure but performing similar functions are known as analogous organs.
• Vestigial organs: Organs that are reduced and have become functionless in an organism, but were functional in their ancestors are called vestigial organs.

III. Evidences from vestigial organs: Organs of the body which are non-functional but they are functional in some other organisms are called vestigial organs:

Morphological evidence of evolution is provided by the presence of vestigial organs of body which are often undesired, degenerated and non-functional. These might have been large and functional in some other animals or in ancestors of those which now possess it in rudimentary forms. e.g„ vermiform appendix in man, muscles of external ear (pinna) in man, nictitating membrane or plica, semilunaris in human eye, wisdom teeth (third pair of molars) tail bone (coccyx) in man, wings of ostrich, hindlimbs in snakes, etc.

Question 7.
What do you mean by organic evolution? How do fossils exhibit evidence to prove organic evolution?
Answer:
Descent with modification in an organism is known as organic evolution.

Evidence of organic evolution from fossils record: Fossils are treated as significant evidence of organic evolution. Fossils are the remains or impressions of ancient organisms preserved in the layers of rock and soil. Fossils only do not prove the theory of organic evolution, yet it evidently prove that gradually complexity increased in body organization. The complexity in the body of organization can be noticed as we study the upper layers. Thus, it can be concluded from above observations :

• The crust of the earth and the organisms living on it underwent change in the course of time.
• The organisms with simple structural organization originated earlier than the complex ones.
• Some of the organisms lived on the earth for short time and became extinct. This was a result of drastic changes in the climate on the earth.

Hence, forth fossils produce bonafide record of such plants and animals which had shown their existence once upon a time and now are extinct or not present exactly in the same form, thus, producing strong evidence in favour of organic evolution.

MP Board Class 12th Biology Solutions