Bhagya

MP Board Class 12th Biology Solutions Chapter 1 Reproduction in Organisms

Reproduction in Organisms NCERT Textbook Questions and Answers

Question 1.
Why is reproduction essential (necessary) for organisms?
Answer:
Reproduction enables the continuity of the species, generation after generation.

Question 2.
Which is a better mode of reproduction sexual or asexual? Why?
Answer:
The sexual mode of reproduction is better because it is biparental reproduction and introduces variation among offsprings and their parents due to crossing over and recombination during gamete formation by meiosis.

Question 3.
Why is the offspring formed by asexual reproduction referred to as clones?
Answer:

• The term clone is used to describe morphologically and genetically similar individuals. It doesn’t need the production of sex organs.
• In asexual reproduction also only one parent is involved in the production of individuals. Newly formed individuals are genetically identical to the parent plant.

Question 4.
Offsprings formed due to sexual reproduction have better chances of survival. Why? Is this statement always true?
Answer:
Offspring formed due to sexual reproduction have better chance of survival because:

• The offspring consists of its hybrid characters which may adapt better with the different environments.
• Genetic variations are introduced among the offspring, which increases the biological tolerance.
• Sexual reproduction occurs in the adverse condition in lower plant kingdom, so sexual spores survive in adverse conditions.
• Sexual reproduction may not always show better chances of survival because the offspring may be inferior to the parents.

Question 5.
How does the progeny formed from asexual reproduction differ from those formed by sexual reproduction?
Answer:
The progeny formed from asexual reproduction remain identical to their parents but the offsprings produced by sexual reproduction shows variation due to genetic recombination.

Question 6.
Distinguish between asexual and sexual reproduction. Why is vegetative reproduction also considered as a type of asexual reproduction?
Answer:
Differences between Asexual and Sexual reproduction:

S.No.	Asexual reproduction	Sexual reproduction
1.	In this type of reproduction, only one parent is required.	In this type of reproduction two parents of different sexes are required.
2.	Whole-body or a single cell acts as a reproductive unit.	Reproductive units are called gametes which are produced by specific tissues.
3.	Offsprings remain pure, i.e., like their parents.	Offsprings differ from their parents.
4.	It occurs by mitosis cell division.	Gametes are formed by meiosis cell division and zygote develops by mitosis cell division
5.	Variation does not occur.	Variation occurs.

Vegetative reproduction is considered as a type of asexual reproduction because :

• It is uniparental reproduction.
• There is no involvement of gametes or sex cells.
• Cell division and no reductional division take place.
• Vegetative propagules are somatic cells.

Question 7.
What is vegetative propagation? Give two suitable examples.
Answer:
It is the process of multiplication where new plants develop from any portion of vegetative organs of plants without involving the seeds. It occurs in lower as well as higher plants. Example: In sweet potato, roots modified into tubes. In ginger and turmeric stem into the rhizome.

Question 8.
Define:
(a) Juvenile phase
(b) Reproductive phase
(c) Senescent phase.
Answer:
(a) Juvenile phase: It is the pre-reproductive in which all organisms require a certain growth and maturity in life before reproducing sexually.
(b) Reproductive phase: Reproductive phase is the phase in the life cycle, where an organism possesses all the capacity and potential to reproduce sexually. It is the end of the juvenile phase or vegetative phase.
(c) Senescent phase: It is the post-reproductive phase in the life cycle where an organism slowly losses the rate of metabolism, reproductive potential and shows deterioration of the physiological activity of the body.

Question 9.
Higher organisms have resorted to sexual reproduction in spite of its complexity. Why?
Answer:
The mode of reproduction helps to introduce now variation in progenies through the combination of the DNA from 2 different individuals. These variations allow the individual to cope up with various environmental conditions and thus make the organisms better suited for the environment.

Question 10.
Explain, why meiosis and gametogenesis are always interlinked.
Answer:
Gametogenesis (formation of male and female gametes) is associated with a reduction in chromosome number thus, the gamete formed contains half chromosome set of the parental cell. So, gametogenesis is interlinked with meiosis because in meiosis reduction of chromosome number from the diploid set (2n) to haploid set (n) takes place.

Question 11.
Identify each part in a flowering plant and write whether it is haploid (n) or diploid (2n).
Answer:

Question 12.
Define external fertilization mention its disadvantages.
Answer:
The fusion of compatible gametes (Male and female) outside the body of an organism is called external fertilization, e.g., in Frog.
Disadvantages of external fertilization:

• It requires a medium for fusion of gametes.
• The young ones are often exposed to predators.
• After fertilization, offsprings are produced large in number but no parental care is provided

Question 13.
Differentiate between a Zoospore and Zygote.
Answer:
Differences between Monera and Protista:

S.No.	Zoospore	Zygote
1.	These are endogenously, asexually	A zygote is a diploid cell formed by fusion
3.	Zoospores take part in dispersal.	The zygote does not have a significant role in dispersal.
3.	Zoospores take part in dispersal.	The zygote does not have a significant role in dispersal.

Question 14.
Differentiate between Gametogenesis and Embryogenesis.
Answer:
Differences between Gametogenesis and Embryogenesis:

S.No.	Gametogenesis	Embryogenesis
1.	It is the formation of gametes from meiocytes.	It is the formation of an embryo from a zygote cell.
2	This is a pre-fertilization event.	This is a post-fertilization event.
3.	It occurs inside reproductive organs.	It occurs outside or inside the female body.
4.	It produces haploid gamete.	It gives rise to diploid embryos.
5.	The cell division during gametogenesis is meiotic in diploid organisms.	The cell division during embryogenesis is mitotic in diploid organisms.

Question 15.
Describe the post-fertilization changes in a flower.
Answer:
After fertilization, the ovule converts into the seed and the whole ovary develops into a complete fruit. The petals and sepals dried and fall off. The fate of other parts is

• The ovary wall forms the pericarp of the fruit. It may become fleshy, juicy or dry.
• The integument of the ovule is converted into seed coat. The outer integument forms the tesla and the inner into tegmen.
• Egg of the ovule divides meiotically and forms the multicellular diploid embryo.
• Polar nuclei as a result of triple fusion from the endosperm. It accumulates food and functions as a nutritive tissue for the developing embryo.

Question 16.
What is a bisexual flower? Collect five bisexual flowers from your neighborhood and with the help of your teacher find our their common and scientific names.
Answer:

S.No.	Common Name	Scientific Name
1.	China rose	Hibiscus rosa sinensis
2	Chandni	Ervatamia divaricata
3.	Makoy	Solatium nigrum
4.	Sunflower	Helianthus annuus
5.	Mustard	Brassica compestris.

Question 17.
Examine a few flowers of any cucurbit plant and try to identify the staminate and pistillate flowers. Do you know any other plant that bears unisexual flowers?
Answer:
In oviparous animals, the fertilized egg covered over by a calcareous shell. After a period of enucleation, the egg hatches out into young one i.e. outside the body of the parent. But in viviparous animals, the zygote develops into a young one inside the body of female organism. After attaining the proper development young ones are delivered out of the body of the female organism. Because of getting proper embryonic care and protection, the chances of survival of young one is greater in viviparous animals.

Question 18.
Why are offspring of oviparous animals at a greater risk as compared to offspring of viviparous animals?
Answer:
In viviparous animals, the young one develops inside the body of the female organism. As a result of this, the young one gets better production and nourishment for proper development. In case of oviparous animals, they lay eggs and the young ones develop inside the calcareous shell, outside the body of the female. So, the young ones are not effectively protected and nourished and are vulnerable, to predators so, they are at a greater risk as compared to the offsprings of the viviparous animals.

Reproduction in Organisms Other Important Questions and Answers

Reproduction in Organisms Objective Type Questions

1. Choose the Correct Answers:

Question 1.
Callose wall is found: (CBSE PMT 2007)
(a) In male gamete
(b) In ovum
(c) In pollen grain
Answer:
(d) In megaspore mother cell.

Question 2.
Name the plant in which new plant arise from the notches of leaves through vegetative propagation: (AFMC2012)
(a) Asparagus
(b) Chrysanthemum
(c) Agave
(d) Bryophyllum.
Answer:
(d) Bryophyllum.

Question 3.
Which type of vegetative propagation is occurs in banana: (AMU 2012)
(a) From tuber
(b) From rhizome
(c) From bulb
(d) From stolen.
Answer:
(b) From rhizome

Question 4.
Which of the following is viviparous:
(a) Tortoise
(b) Bony fish
(c) Hummingbird
(d) Whale
Answer:
(d) Whale

Question 5.
Which of the following is characteristics of the ‘clone’:
(a) Similar to ancestors in genetic character
(b) A group of plants developed in vegetative propagation
(c) Plants developed from same parents
(d) All of the above.
Answer:
(d) All of the above.

Question 6.
Organism which give birth to young ones:
(a) Viviparous
(b) Amphibians
(c) Oviparous
(d) Coelomate.
Answer:
(a) Viviparous

Question 7.
Set of chromosome found in zygote:
(a) X
(b) 2X
(c) 3X
(d) 4X.
Answer:
(b) 2X

Question 8.
The plant which can be obtained same as parent plant:
(a) Through seeds
(b) Through fruits
(c) By cutting the stem
(d) By hybridization.
Answer:
(c) By cutting the stem

Question 9.
Vegetative propagation in potato is:
(a) By rhizome
(b) By bulb
(c) By stem
(d) By tuber.
Answer:
(d) By tuber.

Question 10.
Which of the following is oviparous animal:
(a) Bat
(b) Whale
(c) Penguin
(d) Amoeba.
Answer:
(c) Penguin

2. Fill in the Blanks:

1. Reproductive organs in plants are developed in ……………….. phase.
2. ……………….. nucleus are present in pollen tube of angiosperms.
3. The ……………….. are not form in Rose and Banana, therefore, reproduction occurs through ………………..
4. Reproductive organs of animals are differentiate in ……………….. stage.
5. Eichomia propagate through ………………. in water.
6. Rate of multiplication is greater ……………….. reproduction than ……………….. reproduction.

Answer:

1. Adolescence
2. Three
3. Seeds, Vegetative propagation
4. Embryo
5. Offset
6. Sexual, Asexual.

3. Match the Following

Answer:

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

Answer in One Word/Sentence:

1. What we called uniparental structure formed from asexual reproduction which is genetically and morphologically similar.
2. Write the name of an algae reproduce by means of zoospores.
3. Animal reproduce asexually.
4. What we called spores having flagella.
5. In Bryophyllum what kind of bud reproduce vegetatively ?

Answer:

1. Clone
2. Chlamydomonas
3. Spongilla
4. Zoo-spores
5. Adventitious bud.

Reproduction in Organisms Very Short Answer Type Questions

Question 1.
What is meant by life span ?
Answer:
The period from birth to the natural death of an organism is called life span.

Question 2.
Give definition of fertilization.
Answer:
Fertilization is a process in which male and female gamete fused to form the zygote.

Question 3.
What is clone ?
Answer:
Morphologically and genetically similar individuals who are produced by single parent is called clone.

Question 4.
Give the name of an organism in which asexual reproduction occurs through conidia.
Answer:
Penicillum.

Question 5.
In which plant vegetative propagation occurs through rhizome ?
Answer:
In Ginger, Termeric.

Question 6.
Give the name of an organism in which transverse binary fission occurs.
Answer:Paramoecium.

Question 7.
What is aging ?
Answer:
When humans are not capable for reproduction is known as aging.

Question 8.
Give two examples of Hermaphrodite plants.
Answer:
Cucurbita and Coconut are hermaphrodite plant.

MP Board Class 12th Biology Solutions

MP Board Class 9th General English Grammar Determiners

Determiner is a word that comes before a noun and determines its number or quantity.
Determiner वह शब्द है जो किसी Noun से पूर्व प्रयोग किया जाता है व उसकी संख्या या मात्रा को निर्धारित करता है।

Commonly used determiners are-a, an, the, some, any, much, several, few, little, each, enough, every, both, all, either, neither, half, many, etc. – Uses of some determiners are given below.

Any (कोई)
Any का प्रयोग countable व uncountable nouns के साथ Negative व Interrogative वाक्यों में किया जाता है।

जैसे-
(i) Father has not taken any food.
पिताजी ने कुछ भी नहीं खाया है।

(ii) I am not going anywhere.
मैं कहीं नहीं जा रहा हूँ।
(iii) There is not any milk in the pot.
बर्तन में कुछ भी दूध नहीं है।

(iv) Do you want any money?
क्या तुम्हें कुछ धन की आवश्यकता है?

Enough (पर्याप्त)
जब कोई वस्तु जरूरत या इससे थोड़ी ज्यादा संख्या या मात्रा में हो तो countable Runcountable दोनों के साथ इसका प्रयोग किया जाता है। जैसे

(i) You have taken enough food.
तुमने पर्याप्त भोजन कर लिया है।

(ii) Do you not have enough milk?
क्या तुम्हारे पास पर्याप्त दूध नहीं है?

(iii) Enough has been said by you on this matter.
तुम्हारे द्वारा इस मामले पर काफी कहा जा चुका है।

(iv) Father has not provided me enough money.
पिताजी ने मुझे पर्याप्त धन नहीं प्रदान किया है।

(v) Enough flowers have been plucked, now leave this work.
पर्याप्त फूल तोड़े जा चुके हैं, अब यह काम छोड़ दो।

Some (कुछ)

Some का प्रयोग countable व uncountable nouns से पूर्व Affirmative sentences में (Negative व Interrogative में नहीं) उस वस्तु के लिए किया जाता है जो Enough से कम किन्तु उसके बहुत कुछ पास होती है। जैसे-

(i) There is some milk in the pot.
बर्तन में थोड़ा दूध है।

(ii) He has given me some money to start my business.
उसने मुझे अपना व्यापार प्रारम्भ करने के लिए कुछ धन दिया है।

(iii) I have some books on this subject.
इस विषय पर मेरे पास कुछ पुस्तकें हैं।

(iv) The officer has received some complaints from people against the clerk.
ऑफिसर को क्लर्क के विरुद्ध कुछ शिकायतें प्राप्त

No (Not any) (कुछ नहीं)
No em countable singular, countable plural : और uncountable nouns के साथ किया जाता है। इसका उपयोग pronoun के समान नहीं किया जा सकता।

जैसे
(i) I have not read any book.
= I have read no book.

(ii) She did not bring any.copy.
= She brought no copy.

(iii) His brothers do not do anything.
= His brothers do nothing.

(iv) Your sister has not taken any rice.
= Your sister has taken no rice.

(v) Do you not play any game?
= Do you play no game?

Many (कई)
कोई Countable noun जब पर्याप्त से ज्यादा मात्रा में होता है तब उससे पूर्व Many का प्रयोग किया जाता है। जैसे

(i) Many people will not agree to it.
कई व्यक्ति इसके लिए नहीं मानेंगे।

(ii) Sohan has written many books.
सोहन ने कई किताबें लिखी हैं।
(iii) Does she sell many clothes?.
क्या वह कई कपड़े बेचती है?

(iv) Many people do not know me.
कई लोग मुझे नहीं जानते हैं।

Much (ज्यादा)
Much का प्रयोग uncountable nouns के साथ अधिकतर
(i) negative sentences में,
(ii) questions में, तथा
(iii) subject noun के पूर्व या उसके स्थान पर किया जाता है।

जैसे-
(i) There is not much milk in the glass.
गिलास में ज्यादा दूध नहीं है।

(ii) I could not eat much of it.
मैं ज्यादा नहीं खा सकता था।

(iii) Does he spend much of his money on books?
क्या वह अपना ज्यादा धन पुस्तकों पर व्यय करता

(iv) Did you have much difficulty in finding the place?
क्या तुम्हें वह स्थान ढूँढ़ने में बहुत कठिनाई हुई?

(v) How much money would they need?
उन्हें कितने धन की आवश्यकता होगी?

(vi) Let them take as much as they like.
उन्हें जितने चाहिए उतना लेने दें।

(vii) This is too much, I won’t be able to eat all of it.
यह बहुत अधिक है, मैं यह सब नहीं खा सकता।

Note-More तथा most दोनों many व much की क्रमशः comparative व superlative degree हैं।

Each/Every (प्रत्येक)
In every the attention is focussed on the collection of units with emphasis on the units (every= all). Every में हमारा ध्यान units के संग्रह पर होता है। Every का प्रयोग दो से अधिक के लिए किया जाता है।

In each attention is focussed on units considered one by one individually and separately.
Each में हमारा ध्यान units पर एक-एक करके एकाग्र किया जाता है। Each का प्रयोग दो या दो से अधिक दोनों के लिए किया जाता है। जैसे

1. Each boy participated in the game.
2. Each satellite has its own orbit.
3. Every girl won the prize.
4. I go to him after every two days.
5. The teacher gave marks to each boy.

Few (थोडे)
इसका प्रयोग Countable Nouns के पूर्व कम अर्थात् पर्याप्त नहीं के अर्थ में किया जाता है। जैसे

(i) There are few oranges on the table.
मेज पर थोड़े सन्तरे हैं।

(ii) The benefits of this scheme are few.
इस योजना के बहुत कम लाभ हैं।

(iii) Few of us will take part in it.
हममें से कुछ इसमें हिस्सा लेंगे।

(iv) The gardener plucked few leaves.
माली ने कुछ पत्तियाँ तोड़ीं।

A Few (बहुत थोड़े, कुछ)
(i) A few persons attended the meeting.
बहुत थोड़े से लोग सभा में उपस्थित हुए।

(ii) He gave me a few pencils.
उसने मुझे बहुत थोड़ी पेंसिलें दीं।

(iii) She knew a few things about me.
वह मेरे बारे में कुछ चीजें जानती थी।

(iv) A few of my friends are non-vegetarian.
मेरे कुछ मित्र माँसाहारी हैं।

The Few थोड़े (बचे हुए)

(i) The few oranges left were rotten.
बाकी बचे हुए सन्तरे सड़े हुए थे।

(ii) He was helped by the few persons standing there.
वहाँ खड़े हुए बाकी बचे लोगों ने उसकी मदद की।

(iii) The few girls standing there were of class X.
वहाँ खड़ी लड़कियाँ कक्षा दस की थीं।

Little (थोड़ा)
किसीuncountable noun की मात्रा थोड़ी अर्थात् अपर्याप्त के अर्थ में होने पर little का प्रयोग किया जाता है।

जैसे
(i) There is little water in the glass.
ग्लास में थोड़ा पानी है।

(ii) Give me little oil.
मुझे थोड़ा तेल दो।

(iii) He earned little money.
उसने थोड़ा धन कमाया।

(iv) There is little hope of her recovery.
उसके. अच्छा होने की थोड़ी उम्मीद है।

A Little (थोड़ा मात्रात्मक)

(i) A little knowledge is dangerous.
थोड़ा ज्ञान खतरनाक है।

(ii) Will you take a little coffee?
क्या तुम थोड़ी कॉफी लोगे?

(iii) He knows a little English,
वह थोड़ी अंग्रेजी भाषा जानता है।

(iv) I have a little time for studying.
मेरे पास पढ़ने का बहुत कम समय है।

The Little (थोड़ा)
(i) Ram cares for the little ones.
राम छोटे बच्चों की देखभाल करता है।

(ii) The cat drank the little milk.
बचा हुआ थोड़ा दूध बिल्ली पी गई।

(iii) He tried to spend the little money he had.
उसने अपने पास बचे हुये थोड़े से धन को खर्च करने की कोशिश की।

(iv) The little experience he had, helped him much.
उसके पास जो थोड़ा अनुभव था उसने उसकी काफी मदद की।

Whole (सम्पूर्ण)
इसके पूर्व प्रायः ‘the’ का या किसी possessive का प्रयोग होता है।

जैसे-
(i) The whole world thinks so.
सारा संसार ऐसा सोचता है।

(ii) He paid his whole attention to his studies.
उसने अपना सारा ध्यान अपने अध्ययन पर लगा दिया।

(iii) The merchant sold the whole lot of his goods.
व्यापारी ने अपना सारा माल बेच दिया।

(iv) Please take the whole loaf of bread.
ब्रेड का पूरा हिस्सा ले लीजिए।

None (कोई नहीं) No one (None)
(i) Father did not give money to any one.
= Father gave fruit to none.

(ii) She took none with her.
(iii) No one played with him.
(iv) She spoke to none.
(v) No one is so happy as you.
None is so happy as you.

All (सब)

प्रयोग-

1. Countable plural व uncountable nouns के साथ
2. Nouns के पूर्व determiners के उपयोग के साथ
3. Personal pronouns determiners + nouns के साथ
4. Pronouns के समान “किया जा सकता है।

जैसे-
(i) All animals have to eat in order to live.
सभी पशुओं को जीने के लिए खाना होता है।

(ii) All timber must be chemically treated.
सब इमारती लकड़ी पर रासायनिक क्रिया आवश्यक

(iii) All that glitters is not gold. .
वह सब जो चमकता है सोना नहीं होता।

(iv) All of his money was stolen.
उसका सारा धन चोरी हो गया।

(v) He has two brothers and two sisters. All are teachers.
उसके दो भाई व दो बहनें हैं। सभी शिक्षक हैं।

(vi) (a) He was here all day.
(=The whole of the day).
वह यहाँ पूरे दिन रहा।

(b) He was here every day.
(= don’t miss a single day).
वह यहाँ प्रत्येक दिन रहा।

Exercise-
1. Fill in the correct determiners :

1. …….. pages of this book are torn.
2. He hasn’t got ……… money now.
3. ……… milk left in the pot has spilt.
4. She worked the ………. night.
5. Have you seen ………. cow on your way?
6. I want …….. flowers. :
7. You have ……… right to say so.
8. Not ……… has been done in this field.
9. There are ……. flowers in this garden.
10. There aren’t ……. good books on the subject.
Answer:
1. Some,
2. any,
3. The little,
4. whole,
5. any,
6. some,
7. no,
8. much,
9. many,
10. any.

Exercise-2

Fill in the blanks with the suitable determiner:
1. There is hardly ……… rice left.
2. He gave me ………. money.
3. You have ………. right to say so.
4. There is ……….. water in the river.
5. His ………. life was spoilt.
6. ……… the boys are present.
7. ……… boy got a prize.
8. ………. of us liked him.
9. How ………. ink is left in the bottle?
10. Last night ………. thieves entered the house.
Answer:
1. any,
2. some,
3. no,
4. a little,
5. whole,
6. All,
7. Each,
8. None, All,
9. much,
10. some.

Exercise-3

Rearrange the following to make meaningful sentences.
1. I/a little brought/apple juice/market/from the.
2. little/there is/success/hope/of his.
3. he/hardly/any/money/has.
4. in/this/book/are there/pages/how/many?
5. social work/for/time/spare/some/you/can’t?
Answer:
1. I brought a little apple juice from the market.
2. There is little hope of his success.
3. He hardly has any money.
4. How many pages are there in this book?
5. Can’t you spare some time for social work?

MP Board Class 9th English Solutions

MP Board Class 9th General English Grammar Modals

Modals विशेष प्रकार की Helping verbs हैं जो मुख्य (Finite) verb के Mood (भाव) को प्रकट करने में सहायता करती हैं।

Modals के बाद not लगाकर वाक्य Negative बन जाता है।

Will, shall, should, would, can, could, may, might, ought, need, dare, has to, have to, had to, ought to Modals हैं। आपके पाठ्यक्रम में सिर्फ has to, have to, had to, must, ought to, need, should और इनके negative forms हैं।

Modals की निम्न विशेषताएँ हैं
(1) यह कभी अकेला प्रयुक्त नहीं होता वरन् सदैव किसी मुख्य क्रिया (main verb) के साथ ही आता है।

जैसे-
(i) You should wait for half an hour.
(ii) I had to go there.

(2) Has to व have to को छोड़कर अन्य Modals पर Subject के Number तथा Gender का कोई प्रभाव नहीं पड़ता।

Uses of Some Modals
1. Have to/Had to/Has to (and their negatives)
इनका प्रयोग बाध्यता व्यक्त करने के लिए किया जाता है।

I. (i) I had to bring his clothes.
मुझे उसके कपड़े लाने पड़े।

(ii) You have to bow before him.
तुम्हें उनके सामने झुकना पड़ता है।

(iii) Ramesh had not to eat it.
रमेश को यह नहीं खाना पड़ा।

(iv) She has to go there.
उसे वहाँ जाना पड़ा।

(v) Sheela has not to fetch water in the morning.
शीला को सुबह पानी नहीं लाना पड़ता है।

(vi) I have not to clean my room these days.
‘मुझे अपना कमरा इन दिनों साफ नहीं करना पड़ता है।

अत: ‘Have to’ व उसके negative का प्रयोग first person, second person तथ third person, plural pronouns के साथ present tense में किया जाता है।

‘Has to’ व उसके negative का प्रयोग 3rd person singular number (he, she, it, name, of a person आदि) के साथ Present Tense में किया जाता है

‘Had to’ व उसके negative का प्रयोग Past Tense में सभी persons तथ numbers के साथ किया जाता है

Exercise-1

Fill in the blanks with has to/have to/had to
1. I ……… wear the shirt without ironing.
2. The teachers don’t ……… wear any uniform.
3. We ……… work till midnight.
4. The driver ……… drive the car fast.
5. His mother ……… go away.
6. You don’t ……… worry about it.
Answer:
1. had to,
2. have to,
3. have to,
4. has to,
5. had to,
6. have to.

Exercise-2

Rewrite these sentences into negative

1. He has to pass.
2. They have to write to his father…
3. He has to agree with me.
4. Your sister has to come here.
5. We had to throw it.
Ans.
1. He has not to pass.
2. The have not to write to his father.
3. He has not to agree with me.’
4. Your sister has not to come here.
5. We had not to throw it.

(2) Must

Must is used –
(1) To express compulsion (बाध्यता) जैसे-
(i) You must deposit the money by tomorrow.
तुम्हें रुपये कल तक जमा कर देने चाहिए।
(ii) They must obey the rules.
उन्हें नियमों का पालन करना चाहिए।

(2) To express prohibition (निषेध) जैसे-
(i) You must not come home late.
तुम्हें घर देर से नहीं आना चाहिए।
(ii) Students must’not talk in the classroom.
विद्यार्थियों को कक्षा में बात नहीं करनी चाहिए।

(3) To advice in the form of order.
जैसे-
Mother said to me, “You must lock the doors properly.”
माँ ने मुझसे कहा, “तुम्हें दरवाजे ठीक तरह से बन्द करने चाहिए।”

Exercise-3

Fill in the blanks with must/must not
1. You ……… try your luck.
2. We ……… go there.
3. I………. work hard now.
4. You ……… roam about like this.
Answer:
1. must,
2. must,
3. must,
4. must not.

(3) Should

Should का प्रयोग advice, prohibition, duty, probability or expectation, condition, intention, suggestion इत्यादि को बताने के लिए किया जाता है।

You should consult the doctor immediately.
तुम्हें शीघ्र ही डॉक्टर से परामर्श करना चाहिए।

Boys should be present daily.
लड़कों को प्रतिदिन उपस्थित रहना चाहिए।

Exercise-4

Fill in the blanks using should/should not
1. The peon ……… ring the bell.
2. You ……… tell lies.
3. All of you ……… come in time.
4. I ……… let her down.
5. People ……… spit on the walls.
Answer:
1. should,
2. should not,
3. should,
4. should not,
5. should not.

(4) Ought to/Ought not to

‘Ought to’ का प्रयोग नैतिक कर्तव्य (moral obligation) या सामाजिक बन्धक (binding) बताने के लिए किया जाता है। इसके बाद सदैव verb की Ist form आती है।

जैसे-
You ought to obey your parents.
तुम्हें अपने माता-पिता का कहा मानना चाहिए।

Exercise-5
Fill in the blanks using ought to/ought not to.
1. You ……… obey the traffic rules.
2. Children ……… back answer their elders.
3. You ……… abuse others.
4. People ……… take their own decisions.
5. We ……. be kind to animals.
Answer:
1. ought to,
2. ought not to,
3. ought not to,
4. ought to,
5. ought to

(5) Need/Needn’t

सहायक क्रिया के रूप में need का प्रयोग नकारात्मक और प्रश्नवाचक वख्यों में होता है Need बन्धन या अनिवार्यता को प्रकट नहीं करना

मुख्य Verb के रूप में need का अर्थ होता है to stand. in need of.
1. You need not go there. (Negative)
2. Need he go there? (Interrogative)
3. I need your help. (main verb 264 )

Defective verb के रूप में इसका अर्थ necessity होता है।

जैसे-
(i) You need not pay the fee.
(ii) He need not insist for it.

Exercise-6

Fill in the blanks using need (s) needn’t
1. You ……… go to the hospital now.
2. Uncle Sam ……… your help.
3. It is the ……… of the time to speak the truth.
4. ……. she stay there?
Answer:
1. need not,
2. needs,
3. need,
4. Need.

Exercise-7

Rearrange the following words to make meaningful sentences.

1. Tomorrow/school/to/go/I/must.
2. Early/ought to/you/rise.,
3. Work/night/I/have to/till.
4. Bicycle/man/sell/had to/poor/the/his.
Ans.
1. I must go to school tomorrow.
2. You ought to rise early.
3. I have to work till night.
4. The poor man had to sell his bicycle.

MP Board Class 9th English Solutions

MP Board Class 12th Biology Solutions Chapter 16 Environmental Issues

Environmental Issues NCERT Textbook Question and Answers

Question 1.
What are the various constituents of domestic sewage? Discuss the effects of sewage discharge on a river.
Answer:
Domestic sewage are the waste originating from the kitchen, toilet, laundry and other sources. They contain impurities such as suspended solid (sand, salt, clay), colloidal materials (faecal matters, bacteria, plastic and cloth fiber), dissolved materials (nitrate, phosphate, calcium, sodium, ammonia) and disease-causing microbes.

When organic wastes from the sewage enter the water bodies, they serve as a food source for microorganisms such as algae and bacteria. As a result, the population of these microorganisms in the water body increases. Here, they utilize most of the dissolved oxygen for their metabolism. This results in an increase in the levels of BOD in river water and results in the death of aquatic organisms. Also, the nutrients in the water lead to the growth of planktonic algal, causing algal bloom. This causes deterioration of water quality and fish mortality.

Question 2.
List all the wastes that you generate at home, school or during your trips to other places, which could you very easily reduce. Which would be difficult or rather impossible to reduce?
Answer:

• At home – Kitchen wastes, food-left overs, old torn clothes, papers, carry bags, cotton, broken articles (glass, crockery), leather, plastic, cans etc.,
• At school – Pencil, pencil peels, rubbers, pens, chalk, paper, food, grit etc.,
• At trips – Food, carry bags, food wrappers, water bottles, cups, spoons, plate, faeces and urination in open air.
• Wastes which can be reduced – Biodegradable wastes e.g. papers, rags, food, leather articles, others which are recyclable ones in house or locality itself.
• Which cannot be reduced – Glass, tin, metals, plastics, polythene. They are recycled and reused. Also as landfills. So nonbiodegradable are to be sold to ragpickers.

Question 3.
Discuss the causes and effects of global warming. What measures need to be taken to control global warming?
Answer:
Global warming is defined as an increase in the average temperature of the Earth’s surface due to the greenhouse effect.

Causes of global warming: Global warming occurs as a result of the increased concentration of greenhouse gases in the atmosphere. Greenhouse gases include carbon dioxide, methane and water vapour. These gases trap solar radiation released back by the earth. Global warming is a result of industrialization, burning of fossil fuels, and deforestation.

Effects of global warming: Global warming is defined as an increase in the average temperature of the Earth’s surface. It has been observed that in the past three decades, the average temperature of the Earth has increased by 0-6°C. As a result, the natural water cycle has been disturbed resulting in changes in the pattern of rainfall. It also changes the amount of rainwater. Also, it results in the melting of polar ice caps and mountain glaciers, which has caused a rise in the sea level, leading to the inundation of coastal regions.

Control measures for preventing global warming:

• Reducing the use of fossil fuels
• Use of bio-fuels
• Improving energy efficiency
• Use of renewable sources of energy such as CNG, etc.
• Reforestation.
• Recycling of materials.

Question 4.
Match the items given in column A and B :

Answer:

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

Question 5.
Write critical notes on the following :
(a) Eutrophication.
(b) Biological magnification.
(c) Groundwater depletion and ways for its replenishment
Answer:
(a) Eutrophication: It is the natural ageing process of lake caused due to nutrient enrichment. It is brought down by the runoff of nutrients such as animal wastes, fertilizers, and sewage from land which leads to increased fertility of the lake. As a result it causes a tremendous increase in the primary productivity of the ecosystem. This leads to increased growth of algae, resulting into algal blooms. Later, the decomposition of these algae depletes the supply of oxygen, leading to the death of other aquatic animal life.

(b) Biological magnification: The increase in the concentration of harmful non-biodegradable substances into higher tropic level is called biological magnification. DDT used to protect the crops reach the soil and are absorbed by plants with water and minerals from the soil. Due to rain, these chemicals can also enter water sources and into the body of aquatic plants and animals. As a result, chemicals enter the food chain. Since, these chemicals cannot be decomposed, they keep on accumulating at each trophic level. The maximum concentration is accumulated at the top carnivore’s level.

The producers (phytoplankton) were found to have 0 04 ppm concentration of DDT. Since many, types of phytoplankton were eaten by zooplankton (consumers), the concentration of DDT in the bodies of zooplankton as found to be 0-23ppm. Small fish that feed on zooplankton accumulate more DDT in their body. Thus, large fish (top carnivore) that feed on several small fish have the highest concentration of DDT.

(c) Groundwater depletion and ways for its replenishment: The level of ground¬water has decreased in recent years. The source of water supply is rapidly diminishing each year because of an increase in the population and water pollution. To meet the demand of water, water is withdrawn from water bodies such as ponds, rivers, etc.

As a result, the source of groundwater is depleting. This is because the amount or groundwater being drawn for human use is more than the amount replaced by rainfall. Lack of vegetation cover also results in very small amounts of water seeping through the ground. An increase in water pollution is another factor that has reduced the availability of groundwater.

Measures for replenishing groundwater:

• Preventing over-exploitation of groundwater.
• Optimizing water use and reducing water demand.
• Rainwater harvesting.
• Preventing deforestation and plantation of more trees.

Question 6.
Why ozone hole form over Antarctica? How will enhanced ultraviolet radiations affect us?
Answer:
The ozone hole is more prominent over the region of Antarctica. It is formed due to an increased concentration of chlorine in the atmosphere. Chlorine is mainly released ‘from Chlorofluorocarbons (CFC’s) widely used as refrigerants. The CFC’s release chlorine atoms by the action of UV rays on them. The release of chlorine atoms causes the conversion of ozone into molecular oxygen. One atom of chlorine can destroy around 10,000 molecules of ozone and causes ozone depletion.
CF₂Cl₂ → CF₂Cl+ Cl
Cl + O₃ → ClO+O₂
ClO + O₂ → Cl+O₂
The formation of the ozone hole will result in an increased concentration of UV-B radiation on the Earth’s surface. UV-B damages DNA and activates the process of skin ageing. It also causes skin darkening and skin cancer. High levels of UV-B cause corneal cataracts in human beings.

Question 7.
Discuss the role of women and communities in the protection and conservation of forests.
Answer:
Women and communities have played a major role in environmental conservation movements.

The Bishnoi community in Rajasthan strictly believes in the concept of living peacefully with nature. In 1731, the King of Jodhpur ordered his ministers to arrange wood for the construction of his new palace. For this purpose, the minister and the workers went to bishnoi village. There, a Bishnoi woman called Amrita Devi along with her daughter and hundreds of other Bishnoi’s showed the courage to step forward and stop them from cutting trees. They embraced the trees and lost their lives at the hands of soldiers of the king. This resistance by the people of the village forced the king to give up the idea of cutting trees.

The Chipko movement was started in 1974, in die Garhwal region of the Himalayas. In this movement, the women from the village stopped the contractors from cutting forest trees by embracing them.

Question 8.
What measures, as an individual you would take to reduce environmental pollution?
Answer:

• No biomass burning and minimal use of fossil fuels.
• Vehicles – use of minimum pollution vehicles fitted with catalytic converters.
• Smoking – No tobacco smoking and implementation of Kitchen chimneys
• Noise – Not using TV and other gadgets at louder pitch.
• Tree plantation -1 will plant trees around the school, house and also in other places.
• Wastes -1 will dispose of waste property after segregation.

Question 9.
Discuss briefly the following:
(a) Radioactive wastes.
(b) Defunct ships and e-wastes.
(c) Municipal solid wastes.
Answer:
(a) Radioactive wastes: Radioactive wastes are generated during the process of generating nuclear energy from radioactive materials. Nuclear waste is rich in radioactive materials that generate large quantities of ionizing radiation such as gamma rays. These rays cause mutation in organisms which often results in skin cancer. At high dosage, these rays can be lethal. Safe disposal of radioactive wastes is a big challenge. It is recommended that nuclear wastes should be stored after pre-treatment in suitable shielded containers, which should then be buried in rocks.

(b) Defunct ships and e-wastes: Defunct ships are dead ships that are no longer in use. Such ships are broken down for scrap metal in countries such as India and Pakistan. These ships are a source of various toxicants such as asbestos, lead, mercury etc. Thu$,4hey contribute to solid wastes that are hazardous to health. E-waste or electronic wastes generally include electronic goods such as computers, etc.

Such wastes are rich in metals such as copper, iron, silicon, gold, etc. These metals are highly toxic and pose serious health hazards. People of developing countries are involved in the recycling process of these metals and therefore, get exposed to toxic substances present in these wastes.

(c) Municipal solid wastes: Municipal solid wastes are generated from schools, offices, homes, and stores. It is generally rich in glass, metal, paper waste, food, rubber, leather and textiles. The open dumps of municipal wastes serve as a breeding ground for flies, mosquitoes, and other disease-causing microbes. Hence, it is necessary to dispose of municipal solid waste properly to prevent the spreading of diseases. Sanitary landfills and incineration are the methods for the safe disposal of solid wastes.

Question 10.
What initiatives were taken for reducing vehicular air pollution in Delhi? Has air quality improved in Delhi?
Answer:
Initiatives taken were:
A PIL (Public Interest Litigation) was filed before the supreme court of India. Supreme court undertook time-bound measures for reducing pollution by switching over to CNG in public transport, enforcement of Eura II norms, periodic pollution checkup, use of unleaded petrol, catalytic converters in vehicles, and phasing out old vehicles. Air quality has improved significantly. A substantial fall in CO₂ and SO₂ has been found in Delhi between 1997 and 2005.

Question 11.
Discuss briefly the following:
(a) Greenhouse gases
(b) Catalytic converter
(c) Ultraviolet-B.
Answer:
(a) Greenhouse gases: The greenhouse effect refers to an overall increase in the average temperature of the earth due to the presence of greenhouse gases. Greenhouse gases mainly consist of carbon dioxide, methane, and water vapour. When solar radiation reaches the Earth, some of these radiations are absorbed. These absorbed radiations are released back into the atmosphere. These radiations are trapped by the greenhouse gases present in the atmosphere. This helps in keeping our planet warm and thus, helps in human survival. However, an increase in the number of greenhouse gases can lead to an excessive increase in the Earth’s temperature, thereby causing global warming.

(b) Catalytic converter: Catalytic converters are devices fitted in automobiles to reduce vehicular pollution. These devices contain expensive metals such as platinum, palladium, and rhodium that act as catalysts. As the vehicular discharge passes through the catalytic converter, the unburnt hydrocarbons present in it get converted into carbon dioxide and water. Carbon monoxide and nitric oxide released by catalytic converters are converted into carbon dioxide and nitrogen gas (respectively).

(c) Ultraviolet-B: Ultraviolet-B is electromagnetic radiation which has a shorter wavelength than visible light. It is harmful radiation that comes from sunlight and penetrates through the ozone hole onto the earth’s surface. It induces many health hazards in humans. UV-B damages DNA and activates the process of skin ageing. It also causes skin darkening and skin cancer. High levels of UV-B cause corneal cataracts in human beings.

Environmental Issues Other Important Question and Answers

Environmental Issues Objective Type Questions

1. Choose the Correct Answer:

Question 1.
It is a greenhouse gas:
(a) H₂
(b) CO
(c) CO₂
(d) N₂
Answer:
(c) CO₂

Question 2.
Combustion of fissile fuel resulting in:
(a) SO₂ pollution
(b) NO₂ pollution
(c) N₂O pollution
(d) NO pollution.
Answer:
(a) SO₂ pollution

Question 3.
The causes of the greenhouse effect are the increase in the concentration of:
(a) CO₂
(b) CO
(c) O₃
(d) Nitrogen oxide.
Answer:
(a) CO₂

Question 4.
Which of the following is responsible for the reduction of 03 from the atmosphere:
(a) CFC
(b) NO₂
(c) CO₂
(d) SO₂
Answer:
(a) CFC

Question 5.
Which of the following is highly dangerous radioactive pollutant:
(a) Strontium-90
(b) Phosphorus-32
(c) Sulphur-35
(d) Calcium-40.
Answer:
(a) Strontium-90

6. Causes of acid rain is:
(a) SO₂ pollutant
(b) CO
(c) Insecticide pollution
(d) Dust pollution.
Answer:
(a) SO₂ pollutant

Question 7.
Carbon monoxide is the chief pollutant of:
(a) Water
(b) Air
(c) Noise
(d) Soil.
Answer:
(b) Air

Question 8.
Plants are the purifier of air because:
(a) Respiration
(b) Photosynthesis
(c) Transpiration
(d) Drying.
Answer:
(a) Respiration

Question 9.
Bhopal gas tragedy of 1984 took place because methyl isocyanate related with:
(a) DDT
(b) Ammonia
(c) CO₂
(d) Water.
Answer:
(d) Water.

Question 10.
Maximum ozone layer depletion is caused by:
(a) CO₂
(b) CFC
(c) SO₂
(d) CH4.
Answer:
(b) CFC

Question 11.
Minimata disease is caused by the pollution of:
(a) Mercury and Lead
(b) Mercury and Cadmium
(c) Lead and Tin
(d) Lead and Strontium.
Answer:
(b) Mercury and Cadmium

Question 12.
Taj Mahal is affected by :
(a) Air pollution due to Mathura refinery
(b) Decomposition of marble
(c) Pollution of Yamuna
(d) All of the above.
Answer:
(a) Air pollution due to Mathura refinery

Question 13.
Which of the following is not a pollutant:
(a) Thermal energy plant
(b) Automatic vehicles
(c) Nuclear power energy plant
(d) Hydroelectric project.
Answer:
(d) Hydroelectric project.

Question 14.
The greenhouse effect is increased in temperature of the earth due to:
(a) High concentration of NO₂
(b) High concentration of SO₂
(c) High concentration of CO₂
(d) High concentration of CO.
Answer:
(c) High concentration of CO₂

Question 15.
Greenhouse gases are:
(a) CO₂, CFC, CH_4, NO₂
(b) CO₂, O₂, N₂, NO₂, NH₃
(c) CH₄, N2, CO₂, NH₃
(d) CFC, CO_2, NH₃, H₂
Answer:
(d) CFC, CO₂, NH₃, H₂.

Question 16.
Which of the following is an indicator of water pollutant:
(a) BOD
(b) COD
(c) E. coli
(d) All of the above
Answer:
(a) BOD

Question 17.
Cause of water pollution is:
(a) 2,4-D and insecticides
(b) Smoke
(c) Automatic engines
(d) Aeroplanes.
Answer:
(a) 2,4-D and insecticides

Question 18.
Polluted water is treated by :
(a) Lichen
(b) Fungi
(c) Fern
(d) Phytoplankton
Answer:
(d) Phytoplankton

Question 19.
Which country produces maximum greenhouse gas:
(a) India
(b) Brazil
(c) the USA
(d) France.
Answer:
(c) the USA

Question 20.
Which are not affected by acid rain :
(a) Lithosphere
(b) Plants
(c) Ozone layer
(d) Animals.
Answer:
(c) Ozone layer

Question 21.
Ozone hole causes:
(a) Global warming
(b) Reduction in the rate of photosynthesis
(c) More UV rays come to earth
(d) All of the above.
Answer:
(c) More UV rays come to earth

Question 22.
Highly polluted river of India is :
(a) Ganga
(b) Yamuna
(c) Gomti
(d) Hugh.
Answer:
(a) Ganga

Question 23.
Effect of pollution is forst marked on:
(a) Microorganism
(b) Vegetation
(c) Food crops
(d) None of the above
Answer:
(b) Vegetation

Question 24.
Ozone hole enhances:
(a) UV-radiations reaching earth
(b) Number of characters
(c) Skin cancer
(d) All of the above.
Answer:
(d) All of the above.

2. Fill in the Blanks:

1. …………………… is everything that is around us.
2. …………………. Nature of environmental study is
3. …………………. is the highest layer of the earth.
4. An interacting group of various species in a common location is called……………………..
5. …………………….. is a layer or a set of layers of gases surrounding a planet.
6. ……………………….. is electromagnetic radiation within a certain portion of the electromagnetic spectrum.
7. The is defined as a vertical section of the soil. ……………………….
8. …………………… water is available in plants easily.
9. ……………………. is essential for the respiration of animals which are found in the soil.
10. …………………… is an essential part of the earth for continuity of life.
11. …………………… gas is essential for life.
12. …………………….. fish is used to eat the larva of mosquitoes.
13. Quantity of atmospheric C02 is …………………… by forestation.
14. Soil pollution is caused by ……………………..
15. ………………….. rays are absorbed by ozone layer.

Answers:

1. Environment
2. Multidisciplinary
3. Biosphere
4. Bio-community
5. Atmosphere
6. Light
7. Soil profile
8. Capillary
9. Oxygen
10. Death
11. Oxygen
12. Gambusia
13. Balanced
14. Chemical fertilizers
15. Ultraviolet rays.

3. Match the Following:
(i)

Answer:

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

Answer:

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

Environmental Issues Very Short Answer Type Questions

Question 1.
The surroundings in which a person, animal, or plant lives are called.
Answer:
Environment.

Question 2.
When two individuals can produce fertile offsprings, typically by sexual reproduction is called.
Answer:
Species.

Question 3.
What called, a biological community of interacting organisms and their physical environment?
Answer:
Ecosystem.

Question 4.
Name the lower part of the atmosphere which has found more than 90% gases.
Answer:
Troposphere,

Question 5.
Rays of light which are low wavelength from purple colour rays?
Answer:
Ultraviolet rays.

Question 6.
Light effect of flowering in plants.
Answer:
Photoperiodism.

Question 7.
Smallest particle which are found in soil.
Answer:
Clay.

Question 8.
Water which are absorbed from the atmosphere and held very tightly by the soil particles.
Answer:
Hygroscopic water.

Question 9.
Plants are one marked by short life-cycle.
Answer:
Ephemeral plant.

Question 10.
When an animal or plant resembles another creature or in animate object?
Answer:
Mimicry.

Question 11.
Expand BOD.
Answer:
Biological Oxygen Demand.

Question 12.
Name two gases which are caused air pollution.
Answer:
SO₂ and CO₂.

Question 13.
How much is hearing capacity of man?
Answer:
10 to 12 decibels.

Question 14.
Write the name of highly polluted river of India.
Ans.
Ganga.

Question 15.
What is called the increase in atmospheric temperature due to increased C02 concentration?
Answer:
Greenhouse effect.

Question 16.
Write the full form of DDT.
Answer:
Dichloro Diphenyl Trichloroethane.

Question 17.
How much quantity of CO₂ in atmosphere.
Answer:
0 03%.

Question 18.
Smoke which is caused eye irritation.
Answer:
No.

Question 19.
When the World Environment Day is celebrated?
Answer:
5th June.

Question 20.
Write the full form of PAN.
Answer:
Peroxy Acetyle Nitrate.

Question 21.
Write the full form of CFCs.
Answer:
Chlorofluorocarbons.

Question 22.
How much percent found of CO₂ in atmospheric temperature?
Answer:
60 %.

Environmental Issues Short Answer Type Questions

Question 1.
What is the definition of pollution?
Answer:
Pollution is defined as an undesirable change in physical, chemical or biological characteristics of air, land, water and soil.

Question 2.
Which type of UV-radiations can be lethal to organisms. (CBSE 2005)
Answer:
The most harmful UV-radiation is UV- C has a range of 100-280 nm. They are absorbed by oxygen molecules of the atmosphere. The next goes to UV-B with a range of 280-32 nm wavelength.

Question 3.
What is acid rain? Write any two effects of acid rain on human beings.
Ans.
Acid rain: SO₂ gas is released into the environment by burning of fossil fuels containing sulphide from industries. e.g., Coal. In presence of moisture SO₂ reacts with water and forms the droplets of sulphurous and sulphuric acid in the environment. Likewise nitrogen oxides released from motor vehicles, burning materials and chemical industries also react with water to produce the droplets of nitric acid. The droplets of sulphurous, sulphuric acid and nitric acids fall down on the earth with rainwater and thus, it is known as acid rain.
SO₂ + \(\frac { 1 }{ 2 }\)O₂ → SO₃
H₂O +SO₃ →H₂SO₄
H₂O + NO₂ → HNO₃
Effects on human beings: Skin diseases, irritation, metabolic diseases.

Question 4.
Write a short note on pollution caused due to combustion activities.
Answer:
Combustion of fuel, such as wood, coal, natural gas for cooking and for some other purposes gives out gases like CO₂, CO, SO₂ and consumes oxygen from the air.

Question 5.
Write the effect of air pollution in plants.
Answer:
Effect of air pollution on plants:

• Increase in the concentration of SO₂ causes chlorosis of leaves in plants.
• The cells and chlorophyll of leaves are degraded and fall down.
• Vegetative and reproductive growth is inhibited.
• The development of plant is inhibited.

Question 6.
Thermal power plants are necessary to any country, but they cause harm to the environment and community. Mention how they are harmful to the environment and people. What precautions can be taken to avoid this effect?
Answer:

• Thermal power plants release both particulate and gaseous air pollutants from their smoke stakes.
• When they are inhaled, they cause breathing respiratory disorders, irritation and inflammation of the lungs leading to premature death.

Precautions:

• By installing an electrostatic precipitator, more than 99% of the particulate matter will be absorbed.
• Scrubbers can be used to remove gaseous pollutants.

Question 7.
What is global warming? List four strategies for reducing global warming.
Answer:
Increase in the level of greenhouse gases in the atmosphere causes the rise in global mean temperature called global warming. Four strategies for reducing global warming are:

1. Reducing deforestation.
2. Planting trees.
3. Slowing down the growth of the human population.
4. Reduction in the emission of greenhouse gases.

Question 8.
Write any four measures to control the greenhouse effect
Answer:
Following important measures can be cited as the base steps towards controlling the greenhouse effect:

• The aim is achieved to some extent by reducing the consumption of fossil fuels such as coal and petroleum. This can be achieved by depending more on non-conventional renewable sources of energy such as solar, wind, tidal, biogas, and nuclear energies.
• Disposing of the greenhouse gases as they are formed elsewhere than in the atmosphere.
• By recovering greenhouse gases present already in the atmosphere and disposing of them elsewhere.
• Prevention of deforestation and planting of more trees.

Question 9.
Write a short note:

1. Bio-magnification.
2. UV rays.
3. Bio degradable pollutants.
4. Non-biodegradable.

Answer:
1. Bio-magnification: Bio-magnification, also known as bio-amplification or biological magnification is the increasing concentration of a substance, such as a toxic chemical, in the tissues of organisms at successively higher levels in a food chain.

2. UV rays: Sunlight is the chief source of ultraviolet rays. The rays of sunlight having a wavelength range from 200 to 390 nm are called UV rays.

Effect of UV rays: They have a direct effect on living cells. DNA and other chemical substances in cells are inactivated due to UV rays. Prevention of replication of the DNA molecule and its distortion cause many ill effects.

3. Non-biodegradable: The pollutants which cannot be purified by natural methods are called non-biodegradable pollutants. Plastic products, many chemicals, DDT, long-chain detergents, glass aluminium, mercury salt and other synthetic products manufactured by man come under this category. These non-biodegradable pollutants not only accumulate but often “biologically magnified” as they move in biochemical cycles and along food chains.

4. Biodegradable: The pollutants which are degraded by natural factors and decomposed by natural activities are known as biodegradable pollutants, e.g., Domestic sewage, heat. Domestic sewage can be rapidly decomposed by natural processes or in the engineered system (sewage treatment plant) that enhance nature’s great capacity to decompose and recycle.

Question 10.
What is the effect of SOz in the Environment?
Answer:

Question 11.
Write only the sources of water and air pollution.
Answer:
1. Sources of Water pollution: Following are the chief sources of water pollution:
(a) Human sources :

• Domestic sewage,
• Industrial effluents,
• Agricultural wastes,
• Oil pollution,
• Thermal and nuclear power station.

(b) Natural sources: Water pollution takes place by natural ways like soil erosion, mixing of metallic substances, plant leaves, humus and faecal matter of animals etc.

2. Sources of Air pollution: Following are the chief sources of air pollution:
(a) Human sources:

• Combustion activities,
• Industrial activities,
• Agricultural works,
• Use of solvents,
• Activities concerned with atomic energy.

(b) Natural sources: Volcano and its lava, ash, dust, smoke of forest fire, winds, cyclone. Decomposition of matters in the swamp water and liberation of methane gas and different compounds of hydrogen from forests plants, various pollen grains etc.

Question 12.
Write a note on the effect of water pollution on aquatic organisms.
Answer:
Effect of water pollution on aquatic plants:

• Inorganic nitrates and phosphates in excess amounts stimulate excessive plant growth in lakes and reservoirs. These plants deplete the oxygen contents of the water during the night. This leads to the suffocation of fish and other aquatic life.
• The rapid algal growth leads to the diminishing of nutrients in the medium causing rapid decay of algal filament. This increases the productivity of lake and stream water brought about by nutrient enrichment is called eutrophication.
• The number of microorganisms increases in polluted water.
• Siltation occurs in water.
• The temperature of water increases and the 02 ratios is reduced.

Effect of water pollution on aquatic animals: Animal life depends on aquatic plants. Aquatic animals are affected by water pollution as follows:

• The decrease in the value of B.O.D. resulting in the number of aquatic animals.
• Animals found in freshwater and killed.
• Animal diversity is also decreased and fishes suffer from various types of diseases.
• Terrestrial animals are also affected by the use of polluted water.

Question 13.
Write the measures for the control and prevention of water pollution.
Answer:
Measures for control and prevention of water pollution are:
Preventive measures:

• Use of harmful pesticides and weedicides must be stopped completely.
• Discharge of effluents into rivers, lakes, and sea should be strictly prohibited without treatment.
• Oil spill should be prevented.
• Proper disposal of sewage so, that it does not find its way into water bodies.
• Preventing bathing, washing clothes, throwing dead bodies and other wastes into the water sources.

Curative measures:
1. Adequate wastewater treatment: The domestic sewage and industrial waste should be properly treated before its disposal into waterways.
Wastewater treatment involves three steps:

• Primary treatment: During this treatment large objects and suspended undissolved solids are removed and converted into sludge, a valuable fertilizer.
• Secondary treatment: Aeration is supplied to promote bacterial decomposition, followed by chlorination to reduce its content of bacteria.
• Tertiary treatment: During this phase nitrates and phosphates are removed. The treated water is then released. Sewage treatment is quite expensive and in many developing countries only the first two steps are followed.

2. Treatment of industrial effluents: Industrial effluents should be properly treated to remove the pollutants. These involve neutralization of acids and alkalies, removal of harmful chemicals, coagulation of colloidal impurities, precipitation of metallic compounds, and reducing the temperature of wastes to decrease thermal pollution. Chemical oxidation can be achieved by chlorination through reaction with ozone. However, there are certain chemicals which are difficult to remove.

3. Recycling: One of the best methods of prevention and control of water pollution is the recycling of the various kinds of pollutants and wastes, e.g., Dung of cow and buffalo can be used for the production of gobar gas a cheap source of fuel and also as manure.

Question 14.
Write short notes on air pollution caused due to industries.
Answer:
Industrial pollution is caused by industrial pollutants which are released by the industries such as SO_2, CO₂, CO, H₂S, and hydrocarbons together with dust and smoke. These are produced by the burning of coal and petroleum.

The chemical industries release HCl, Cl₂, nitrogen oxide, oxides of copper, zinc, lead, arsenic, etc. Industrial pollutants cause air pollution and water pollution.

Question 15.
Write preventive measures of sound pollution.
Answer:
Preventive measures of noise pollution:

• Noise pollution can be controlled by designing quieter machines, proper lubrication, and better maintenance of machines. Noise-producing parts of machines may be covered by suitable insulating materials.
• Noise-producing industries should be installed away from residential areas.
• The use of public addressing systems should be restricted at a fixed intensity and hours of the day.
• Stuffing of cotton plugs in the ear or use of ear-muffs and minimize the danger of occupational exposure to noise.
• Trees absorb sound vibrations and thus, reduce noise pollution. Thus, the plantation of trees along highways, the establishment of parks help in reducing noise pollution.
• By use of silencer in all automobiles and engines.

Question 16.
Why do you consider that integrated organic farming is more advantageous?
Answer:
Integrated organic farming is a cyclical, zero-waste process, in which the waste materials from one process are used as nutrients or raw materials for the other process. The resources are utilized to the maximum and the efficiency of production is increased. Since the process support one another, it is an extremely economical and sustainable procedure. There is no need to depend on chemical fertilizers and pesticides as cattle dung is used as manure. Crop residues are decomposed and are used as manure. The dung of animals and crop residues are used to produce biogas, which satisfies the energy needs of the farm.

Question 17.
How many types of pollution are there? Explain in brief.
Answer:
Pollution is of following five types:

1. Air pollution,
2. Noise pollution,
3. Water pollution,
4. Radioactive pollution,
5. Soil pollution.

1. Air pollution: Pyrotechnics results in the release of harmful gases like CO₂, CO, and SO₂ in the environment which produces various types of diseases in living beings.

2. Noise pollution: Pyrotechnics produces unwanted sound dumped into the atmosphere leading to health hazards.

3. Water pollution: Pyrotechnics produces some waste materials, on reaching water it causes water pollution.

4. Radioactive pollution: Pollution created due to radioactive substances is called radioactive pollution. Atomic energy centers and bombarding also cause radioactive pollution.

5. Soil pollution: Any change in physical and chemical characteristic of soil due to addition of unwanted substance which adversely affects the productivity of soil it termed as soil pollution.

Environmental Issues Long Answer Type Questions

Question 1.
Describe the diseases caused due to radioactive pollution.
Answer:
Following diseases are caused by radioactive pollution:

• Leukaemia and bone cancer: In human beings and other animals, radioactive pollution causes blood and bone cancer.
• Ageing: The reproductive capacity of organisms is decreased due to radioactive
  pollution and ultimately causes ageing.
• Epidemic disease: Radioactive pollution causes the decreased rate of antitoxin production which affects the immune system and results in the production of epidemic diseases.
• Nervous system and sensory cells become irritated.
• Radioactive pollution results skin cancer.
• Mutations also take place due to radioactive pollution.
• Thyroid cancer is also produced due to radioactive iodine.

Question 2.
Burning of crackers spread pollution in the environment. Explain.
Answer:
Explosive substances are used in crackers. Crackers are burned for celebration but it causes many harms to the living organisms. Some of the harm effects of burning of crackers are as follows :

1. Air pollution: It releases harmful gases such as CO₂, CO, SO₂ etc. into the atmosphere. Which causes respiratory diseases.

2. Noise pollution: Burning of crackers produces noise which causes noise pollution which effects our hearing capacity, causes headache, increases heartbeat and blood pressure.

3. Water pollution: Waste of burning of crackers are drained into the pond, river with rainwater or through drain which causes harm to aquatic organisms.

4. Soil pollution: Burning of crackers not only produces smoke of harmful gases but its harmful chemicals mixes with soil and pollute it, which makes the soil sterile and reduced growth of plants.

Question 3.
Write an essay on air pollution.
Answer:
Air pollution : Any change in the composition of air is called pollution. The chief reason of air pollution is the releasing of harmful gas in the environment that affectdur eyes, lungs, skins, heart and brain and’produce various disorders in them. Sources of Air polution:

1. Sources of Water pollution: Following are the chief sources of water pollution:
(a) Human sources :

• Domestic sewage,
• Industrial effluents,
• Agricultural wastes,
• Oil pollution,
• Thermal and nuclear power station.

(b) Natural sources: Water pollution takes place by natural ways like soil erosion, mixing of metallic substances, plant leaves, humus and faecal matter of animals etc.

2. Sources of Air pollution: Following are the chief sources of air pollution:
(a) Human sources:

• Combustion activities,
• Industrial activities,
• Agricultural works,
• Use of solvents,
• Activities concerned with atomic energy.

(b) Natural sources: Volcano and its lava, ash, dust, smoke of forest fire, winds, cyclone. Decomposition of matters in the swamp water and liberation of methane gas and different compounds of hydrogen from forests plants, various pollen grains etc.

(A) Effects of air pollution :

• Air pollutant like SO₂ enter the soft tissues causing drying of the mouth, scratching throat and smarting eyes.
• Hydrocarbons and many other pollutants are responsible for causing cancer.
• Oxides of carbon, sulphur and nitrogen diffuse into the blood stream to combine with haemoglobin causing reduction in its oxygen carrying capacity. CO severely damages cardiovascular system and disturbs psychometry functions.
• P.A.N. inhibits Hill reaction and thus, decreases photosynthetic production of an ecosystem.

Control of Air pollution:  Measures for the control of air pollution :

• Industrial smokes must be filtered before releasing it into the atmosphere.
• Tree plantation should be increased and deforestation prevented.
• Use of automobiles should be minimized which reduce the nitrogen contents in the atmosphere.
• The use of crude fuels should be avoided and use of high quality fuels should be recommended.
• Nuclear explosions should be avoided.
• Legal control of air pollution.
• Plantation of air purifying plants.
• Development of parks and gardens in cities.

Question 4.
Name the major air pollutants and their individual effects.
Answer:
Major air pollutants and their individual effects are as follows :

1. Carbon monoxide: It is highly poisonous gas. On entering bloodstream, it combines with hemoglobin to block oxygen transport function. It causes laziness, headache, disturbance of psychometry functions, decrease in visual perception, serious effects on the cardiovascular system etc.

2. Sulphur dioxide: The animals and human population when exposed to SO₂, suffer from respiratory diseases. It causes chest constriction, headache, vomiting and death from respiratory ailments.

3. Hydrogen sulphide: Its rotten egg like smell cause nausea, irritation in eyes and throat.

4. Nitrogen oxide: It inhibits cilia action so that soot and dust penetrate far into the lungs and finally resulting respiratory diseases in human beings and animals. In plants, it causing chlorosis.

5. Aerosoles: These are the chemicals affecting ozone layer of the atmosphere due to which UV rays enter in the atmosphere and causing various diseases in plants and animals.

6. Ammonia: It inflame upper respiratory passage in human beings. In plants, it inhibits seed germination, destruction of chloroplast and inhibition of the growth of roots and shoots.

7. Hydrogen chloride: It affects the leaves of the plants, eyes, respiratory organs of animals and human beings.

8. Hydrocarbons: It causes the yellowing of plants, drying of buds, whereas in man and other animals, mucous glands of the eyes and nose are irritated.

Question 5.
Write down the methods to control soil pollution.
Answer:
Control of Soil pollution: By following, methods soil pollution can be prevented:

• The government should make provisions for latrines and people should not be allowed to litter in open fields.
• Solid wastes such as tin, copper, iron, glass, etc., should not be dumped into the soil.
• The solid wastes should be recycled to form new materials.
• Fertilizers and pesticides should be judiciously used.
• Instead of pesticides to kill pests, biological control methods should be adopted.
• The excretory waste of man and cattle should be used to prepare biogas.
• Clean and well-covered dustbins should be used in villages and cities.
• Closed hollow pipes should be used to collect and discharge liquid wastes.
• To prevent soil erosion, grass, and small plants should be grown.
• Soil management should be adopted.

Question 6.
What are the sources of soil pollution?
Answer:
Sources of soil pollution:

• Acid rainwater and water from mines are the main sources of soil pollution.
• Mixing of debris, waste products with the soil cause soil pollution.
• By excessive use of pesticides and fertilizers, pollute the soil.
• When industrial wastes are discharged into the soil, they also pollute the soil.
• Heavy metals e.g., Cadmium, Zinc, Nickel, Arsenic, etc., are mixed with the soil
  from mines. These metals are harmful to plants as well as primary and secondary consumers, in a food chain. ’
• Bones of dead animals, paper putrified flesh and food, iron, copper, mercury, etc., pollute the soil.
• In our villages and rural areas, where there are no latrines, people go to fields for being at ease. From their stool also the soil is polluted.
• Insecticides like D.D.T. is a very dangerous substance. When these enter the body of consumers from producers, their concentration is increased because these are non-degradable substances. Moreover, these can remain in the atmosphere for upto 15.years.

Question 7.
Explain non-ionizing and ionizing radiation.
Answer:
Types of Radiations on the basis of their action on cells, radiations are of two types:
1. Non-ionising radiations: These include ultraviolet rays (UV rays; 100-300 nm), they have low penetration capacity. These affect only those cells which absorb them. The cause is as follows:

• Sunburn: It includes rupturing of subcutaneous blood capillaries, blisters, reddening of skin and injury to stratum germinativum.
• Snow blindness: It damages eyesight due to damage of corneal cells.
• Inactivation of organic bio-molecules arid formation of thymine dimer in DNA.
• However, they cause cancer, tumor, skin disease, etc.

2. Ionizing radiations: These include X-rays, cosmic rays and atomic radiations. These radiations have low wavelengths but high penetration power. This damages the living cells shifting the electron from one to other bio-molecule. Their harmful effects are as follows :

• Short-range effects: These may appear within few days or a few weeks after exposure. The effects include loss of hair, nails, subcutaneous bleeding, metabolic changes, change in the proportion of blood cells, dead tissues or death of the organisms in high dose.
• Long-range effects: These appear in several months or even several years after their exposure. These cause tumours, cancers, mutations, genetic deformities, shorter life span and developmental defects.

Question 8.
What are sources of noise pollution? Write any four effects of noise pollution.
Answer:
Sources of noise pollution: Noise is either natural such as thunder or man-made. The common sources of noise pollution are :

• Industries such as textile mills, printing-press, engineering establishments, etc.
• Defence equipment and vehicles such as tanks, artillery and rocket launching explosions, practise firing, etc.
• Transport vehicles as trains, trucks, buses, two-wheelers, jet planes, etc. mid accessory noise produced by horns, sirens.
• Other applications as dynamite blasting, use of jackhammers, pile drivers, bulldozer, lawnmowers, etc.

Effects of noise pollution:

• The more acute and immediate effect of noise pollution is impairing of hearing leading to auditory fatigue and may finally lead to deafness.
• Interference with speech communication.
• Noise pollution leads to neurosis, anxiety, hypertension, cardiovascular disease, hepatic stress, giddiness.
• Annoyance leading to ill-temper, bickering, mental disorientation and violent behaviour.
• The high intensity of noise pollution can cause blood vessels to contract, skin becomes pale, muscles to contract and adrenaline to be shot into bloodstream with consequence rise in blood pressure. This ultimately results in tension and nervousness.
• Affects different metabolic activities.

Question 9.
What is the Greenhouse effect? Write any four impacts of the Greenhouse effect
Answer:
Greenhouse effect: The Greenhouse effect may, therefore, be defined as “The progressive warming up of the earth’s surface due to the blanketing effect of man-made CO₂ in the atmosphere. It means the excessive presence of those gases blocked in the infrared radiation from the earth’s surface to the atmosphere leading to an increase in temperature, which in turn would make life difficult on earth to forthcoming future generations.
Four impacts of Greenhouse effects are :

1. Effect on global climate: The climate of earth has never been free of charge. Its composition, temperature and self-cleansing ability have all varied since, the planet first formed. Yet the pace in the past two countries has been remarkable. The atmosphere’s composition in particular has changed significantly faster than it has at any time in human history.

Increase in Greenhouse gases does not increase die temperature of the earth i.e„ it is not uniform. Temperature is normal at poles and is very less at tropics. In Iceland, Greenland, Sweden, Norway, Finland, Alaska, Siberia, the temperature is more, thus at poles, ice starts melting.

2. Effect of Greenhouse Effect on forests: When the atmospheric temperature increases, only those plants can survive which can bear high temperature. Because of this, new species of plants also come into existence, Herbaceous plants can not survive in this high temperature. Plants with high wood Will increase in number. According to a survey if the amount of CO₂ in the atmosphere is doubled, there will be a great decrease in green biomass.

3. Effect on crops: The positive aspect of the greenhouse effect will be on agriculture. Because CO₂ is a natural fertilizer, the plants will grow larger and faster with increasing CO₂ in the atmosphere. At first sight, the abnormal growth of plants might be expected to be beneficial because the yields of major crops might increase, however chances of depletion of characters and productivity of soil are also associated with this.

4. Effect on the ozone layer: During depletion, the chlorine, fluorine, or bromine molecules of CFCs and halogens are converted into reactive free radical form by photochemical reactions from their initial non-reactive sites. Oxides of nitrogen generally inactivate Cl but the lowering of stratospheric temperature changes. NO₂ into non-reactive nitric acid. Thus, Cl or F are free to react with ozone, disintegrating it into O₂ + O.

The tiny ice particles during winter favours the conversion of chlorine into chlorine monoxide, which behaves as a catalytic compound. The abundance of chloromonoxide rich air in the stratosphere continues to rise. Chlorine monoxide reacts with nascent oxygen and thereby gets converted into chlorine. Thus, the cycle continues to destroy the ozone-level.

MP Board Class 12th Biology Solutions

MP Board Class 12th Biology Solutions Chapter 2 Sexual Reproduction in Flowering Plants

Sexual Reproduction in Flowering Plants NCERT Textbook Questions and Answers

Question 1.
Name the parts of an angiosperm flower in which development of male and female gametophyte take place.
Answer:
Development of male gametophyte takes place in anther and female gametophyte in ovary.

Question 2.
Differentiate between microsporogenesis and megasporogenesis. Which type of cell division occurs during these events? Name the structure formed at the end of these two events.
Answer:
Differences between Microsporogenesis and Megasporogenesis:

No.	Microsporogenesis	Megasporogenesis
1.	In this process haploid microspores are formed from diploid microspore motto’cell.	In this process, haploid megaspores are formed from diploid megaspore mother cell.
2	The four microspores formed from a single microspore mother cell are generally aranged in a tetrahedral structure.	The four megaspores formed from a megaspore mother cell are arranged in die from of a linear tetrad.
3.	All the four microspores arranged in a tetrahedral tetrad are functional.	Only one megaspore remain functional while the other three degenerates.

Meiosis Occurs during micro and megasporogenesis microspores (Pollen grain) are formed at the end of micro sporogenesis and female gametophyte (enibro sac) are formed at the end of megasporogenesis.

Question 3.
Arrange the following terms in the correct developmental sequence:
Pollen grain, sporogenous tissue, microspore tetrad, pollen mother cell, male garnets.
Answer:
Sporogenous tissue → Pollen mother cell → Microspore → Tetrad → Pollen grain → Male garnets.

Question 4.
With a neat, labelled diagram, describe the parts of a typical angiosperm ovule.
Answer:
Structure of Ovule: Each ovule consists of the following parts as visible in a longitudinal section:

1. Funicles: It is a stalk-like structure which represents the point of attachment of the ovule to the placenta of the ovary.
2. Hilum: It is the point where the body of the ovule is attached to the funicles.
3. Integuments: They are the outer layers surrounding the ovule that provide protection to the developing embryo.
4. Micropyle: It is a narrow pore formed by the projection of integuments. It makes the point where the pollen tubes enter the ovule at the time of fertilization.
5. Nucellus: It is a mass of parenchymatous tissue surrounded by the integuments from the outside. The nucellus provides nutrition to the developing embryo. The embryo sac is located inside the nucellus.
6. Chalazal: It is the based swollen part of the nucellus from where the integuments originate.

Question 5.
What is mean by monosporic development of a female gametophyte?
Answer:
Out of theTour megaspores, three degenerate and only one remains functional which develops in to a female gametophyte or embryo sac. This is called monosporic development, i.e., when embryosac develops from one single megaspore it is called monosporic embryo sac.

Question 6.
A neat diagram explains the 7-celled, 8-nucleate nature of the female gametophyte.
Answer:
Explanation: Nucleus of the functional megaspore undergoes mitosis resulting in 2-nuclei that move to two opposite poles forming 2-nucleate embryo sac.
Two more mitotic nuclear divisions result in 4-nucleate and later 8-nucleate stages of the embryo sac. so, far no cytokinesis (cytoplasmic division) has taken place.
Now cell walls start to build leading to the organisation of female gametophyte or embryo sac.

Six of the 8-nuclei are bound by cell wall and the remaining 2-celled polar nuclei lie below the egg apparatus in the large central cell.
Seven-celled stage
Three cells are grouped together at the micropylar end and constitute the egg appara¬tus, which is constituted of two synergids and one egg cell.
Three cells at the chalazal end are called antipodals. The large central cell has 2-polar nuclei.
Thus, a typical angiosperm embryo sac at maturity is 7-celled but 8-nucleated as the central cell has 2-nuclei

Question 7.
What are chasmogamous flowers? Can cross-pollination occur in cleistogamous flowers? Give reasons to your answer.
Answer:
Chasmogamous flowers are open flowers with exposed stamens and stigma which facilitate cross-pollination.
No cross-pollination occurs in cleistogamous flowers. As these flowers are closed and never open and thus no transfer of pollen from outside to the stigma of the flower is possible. So there is no occurs cross-pollination.

Question 8.
Mention two strategies evolved to prevent self-pollination in flowers.
Answer:
Self-pollination involves the transfer of pollen from the stamen to the pistil of the same flower. Two strategies that have evolved to prevent self-pollination in flowers are as follows.

(a) In certain plants, the stigma of the flower has the capability to prevent the germination of pollen grains and hence, prevent the growth of the pollen tube. It is a genetic mechanism to prevent self-pollination called self-incompatibility. This may be between the individuals of the same species or between individuals of different species. Thus, incompatibility prevents breeding.

(b) In some plants, the gynoecium matures before the androecium or vice – versa. This phenomenon is known as protogyny or protandry respectively. This prevents the pollen from coming in contact with the stigma of the same flower.

Question 9.
What is self-incompatibility? Why does self-pollination not lead to seed forma¬tion in self-incompatible species?
Answer:
Self-incompatibility is a genetic mechanism to prevent self-pollen from fertilizing the ovules by inhibiting pollen germination or pollen tube growth in the pistil.
In these cases, self-pollination does not lead to seed formation because fertilization is inhibited.

Question 10.
What is the bagging technique? How is it useful in a plant breeding programme?
Answer:
Various artificial hybridization techniques (various crop improvement programmes involve the removal of the anther from bisexual flowers without affecting the female reproductive part (pistil) through the process of emasculation. Then, these emasculated flowers are wrapped in bags to prevent pollination by unwanted pollen grains. This process is called bagging.

This technique is an important part of the plant breeding programme as it ensures that pollen grains of only desired plants are used for fertilization of the stigma to develop the desired plant variably.

Question 11.
What is triple fusion? Where and how does it take place? Name the nuclei involved in triple fusion?
Answer:
Triple fusion refers to the process of fusion of three haploid nuclei. It takes place in the embryo sac.
The 3-nuclei that fuse together are the nucleus of the male gamete and 2-polar nuclei of the central cell to produce a triploid primary endosperm nucleus.

Question 12.
Why do you think the zygote is dormant for some time in a fertilized ovule?
Answer:
The zygote is formed by the fusion of the male gamete with the nucleus of the egg cell. The zygote remains dormant for some time and waits for the endosperm to form, which develops from the primary endosperm cell resulting from triple fusion. The endosperm provides food for the developing embryo and after the formation of endosperm, further development of the embryo from the zygote starts.

Question 13.
Differentiate between:
(a) Hypocotyl and Epicotyl
(b) Colcoptile and Coleorhiza
(c) Integument and Testa
(d) Perisperm and Pericarp.
Answer:
(a) Differences between Hypocotyl and Epicotyl:

No.	Hypocotyl	Epicotyl
1.	lies between the radicle and the point lie between the radicle and the point of attachment of cotyledons is called the hypocotyl.	The region of the embryonal axis that lies between the plumule and cotyledons is called epicotyl.
2.	Hypocotyl pushes the seed above the soil in epigeal germination	Epicotyl pushes the plumule above the soil in hypogeal germination.
3.	It is an important component of the embryonic root system.	It is an important component of the embryonic shoot system.

(b) Differences between Coleoptile and Coleorhiza:

No.	Coleoptile	Coleorhiza
1.	The shoot apex and few leaf primordia are enclosed in the epicotyl region is called coleoptile	The ridicule and rootcap are situated at the lower end of the embryonal axis are enclosed by a protective sheath called coleorhiza.
2	It comes out of the soil.	It remains inside the soil.

(c) Differences Between Integument and Testa:

No.	Integument	Testa
1.	It is the protective covering of the ovule	It is the protective covering of the seed
2.	It is part of pre fertilisation	It is a part of post fertilisation.

(d) Differences between Peris perm and Pericarp:

No.	Perisperm	Pericarp
1.	It is the part of the nucellus which remains in	The ovary is converted into a pericarp after
2	It is a part that belongs to the seed	It is a part that belongs to fruit.
3.	It is usually dry.	It can be dry and fleshy.

Question 14.
Why is apple called a false fruit? Which parts of the flower form the fruit?
Answer:
Fruits derived not from the ovary but from other accessory floral parts are called false fruits. On the contrary, true fruits are those fruits in which fleshy parts develop from an ovary but don’t consist of the thalamus or any other floral parts. In an apple, the fleshy receptacle forms the main edible part. Hence it is a false fruit.

Question 15.
What is meant by emasculation? When and why does a plant breeder employ this technique?
Answer:
Emasculation means the removal of anthers, with forceps, from the flower bud before dehiscence.
Plant breeder employs this technique to prevent contamination of stigma with the undesired pollen. This is useful in artificial hybridisation, where desired pollen is required.

Question 16.
If one can induce parthenocarpy through the application of growth substances, which fruits would you select to induce parthenocarpy and why?
Answer:
Parthenocarpy is the process of developing fruits without involving the process of fertilization or seed formation. Therefore the seedless varieties of economically important fruits such as orange, lemon, grapes etc. are produced using this technique. This technique involves inducing fruit formation by the application of plant growth hormone such as auxins.

Question 17.
Explain the role of tape turn in the formation of pollen grain walls.
Answer:
Tapetum is the innermost layer of the microsporangium. It produces the exine layer of the pollen grains, which is composed of sporopollenin, the most resistant fatty, substance.
During microsporogenesis, the cells of the tapetum produce various enzymes, hormones, amino acids, and other nutritious materials required for the development of pollen grains.

Question 18.
What is apomixis and what is its importance?
Answer:
Apomixis in the mechanism of seed production without involving the process of meiosis and syngamy. It plays an important role in hybrid seed production. The method of producing hybrid seeds by cultivation is very expensive for farmers. Also by sowing hybrid seeds, it is difficult to maintain hybrid characters that segregate during meiosis. Apomixis prevents the loss of specific characters in the hybrid. Also, it is a cost-effective method for producing seeds.

Sexual Reproduction in Flowering Plants Other Important Questions and Answers

Sexual Reproduction in Flowering Plants Objective Type Questions

1. Choose the Correct Answers:

Question 1.
Fertilization process is:
(a) Fusion of male gamete with egg
(b) Transference of pollengrains to stigma
(c) Fusion of polar nucleus with male gamete
(d) Formation of seed from ovule.
Answer:
(a) Fusion of male gamete with egg

Question 2.
Female gametophy te of angiosperms is:
(a) Megaspore mother cell
(b) Ovule
(c) Endosperm
(d) Nucellus.
Answer:
(c) Endosperm

Question 3.
Effect of nector demonstrate by Xenia word on:
(a) Morphological tissue
(b) Root
(c) Flower
(d) Endosperm.
Answer:
(d) Endosperm.

Question 4.
In a diploid flowering plant, no. of chromosomes are 12, then 6 chromosomes will be present in:
(a) Cotyledons cells
(b) Endospermic cells
(c) Synergids cells
(d) Leaf cells.
Answer:
(c) Synergids cells

Question 5.
Seed coats of seed after fertilization develop from:
(a) Integuments
(b) Endosperms
(c) Chalaza
(d) Ovule.
Answer:
(a) Integuments

Question 6.
Perispermis:
(a) Degenerative secondary nucleus
(b)Apomixis
(c) Peripheral part of endosperm
(d) Parthenogenesis.
Answer:
(b)Apomixis

Question 7.
Development of ovary into fruit from ovule without fertilization, the process is called:
(a) Parthenio ovule
(b) Apomixis
(c) Pathenocarpy
(d) Parthenogenesis.
Answer:
(c) Pathenocarpy

Question 8.
Mitotic cell division in an ovule takes place in:
(a) Nucellus
(b) Megaspore mother cell
(c) Macrosporangia
(d) Archisporium.
Answer:
(b) Megaspore mother cell

Question 9.
Development of sporophyte without the fusion of a gamete is called:
(a) Apomixis
(b) Apospory
(c) Apogamy
(d) Pollination.
Answer:
(c) Apogamy

Question 10.
Male gametes are found in angiospermic plants :
(a) In pollengrain
(b) In anther
(c) In ovule
(d) All of these
Answer:
(a) In pollengrain

Question 11.
The function of pollentube is:
(a) Help in pollination
(b) Protection of stigma
(c) Male gamete carrier
(d) All of these
Answer:
(c) Male gamete carrier

Question 12.
Tapetum is a part of:
(a) Male gametophyte
(b) Female gametophyte
(c) Ovary wall
(d) Anther wall.
Answer:
(d) Anther wall.

Question 13.
Cotyledons is situated in monocots:
(a) Axial
(b) Terminal
(c) Basal
(d) In Any Position
Answer:
(a) Axial

Question 14.
Which type of pollination found in sunflower:
(a) Self pollination
(b) Cross pollination
(c) All of the above
(d) None of these.
Answer:
(c) All of the above

Question 15.
Endospermic nucleus are :
(a) Haploid
(b) Diploid
(c)Triploid
(d) None of these.
Answer:
(b) Diploid

Question 16.
Double fertilization is discoverd by: :
(a) By Navaschin
(b) Leuwenhock
(c) Strasburger
(d) Hofmeister.
Answer:
(a) By Navaschin

Question 17.
The type of pollination in which genetically different pollen grains are brought to
stigma is : (AMU 2012)
(a) Xenogamy
(b) Geitonogamy
(c) Cleistogamy
(d) Dichogamy. ,
Answer:
(a) Xenogamy

Question 18.
If the number of chromosome in root cell is 14 then what will be the number of chromosome in synergid cell of in ovule of that parent (BHU2012)
(a) 14
(b) 21
(c) 7
(d) 28.
Answer:
(c)7

Question 19.
Presence of many embryo (Polyembryony) is characters tic feature of: (BHU2012)
(a) Citrus
(b) Mango
(c) Banana
(d) None of these.
Answer:
(a) Citrus

Question 20.
Sporopollenin is formed by the polymerisation of : (BHU2012)
(a) Fat and Phenol
(b) Carotenoid and Fat
(c) Fat and Ester
(d) Carotenoid and Ester.
Answer:
(a) Fat and Phenol

2. Fill in the Blanks:

1. The main function of endosperm in a seed is the storage of ………………
2. Pollination takes place by the agency of bird is called ………………
3. Apple is an example of fruit. ………………
4. Tissue on which ovules are attached is called ………………
5. ……………… types stamens are found in sunflower.
6. In plants development of fruit takes place from ………………
7. One cotyledon of maize is called ………………
8. Tetradynamous stamens are found in ………………
9. ………………is thin in endospermic seed.
10. In ovule …………….. is joined with funiculus.
11. Anther is ……………… in angiospermic plants.
12. ……………… type of pollination are found in Typha.
13. ……………… pollination is occurs in Salvia.
14. Outer wall of pollen grain is called ………………
15. Process of seedless fruit is called ………………

Answer:

1. Food material
2. Omithophilly
3. False
4. Placenta
5. Syngenecious
6. Ovary
7. Scutellum
8. Mustard
9. Cell wall
10. Hylum
11. Reproductive organ
12. Joint
13. Insect
14. Exine
15. Parthenocarpy.

3. Match the Following:

Answer:

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

4. Answer in One Word/Sentence:

1. Name the four whorls of flower.
2. Give the term for plants which produce flower and fruits many times.
3. Name the outer coat of the seed.
4. Give example of plant in which flowers are pollinated by bat.
5. Give the term used for similar calyx and corolla.
6. What parts of the plant produce seed and fruit after fertilization?
7. Name the type of pollination carried out of bat.
8. Give the term for fruit development without fertilization.

Answer:

1. Calyx, Corolla, Androecium and Gynoecium
2. Perrenial plants
3. Seed coat
4. Kadamb
5. Petalloid
6. Ovary
7. Chiropteriphilly
8. Parthenocarpy.

Sexual Reproduction in Flowering Plants Very Short Answer Type Questions

Question 1.
Development of female gametophyte occurs in which cell?
Answer:
By functional megaspore mother cell.

Question 2.
What is the other name of female gametophyte?
Answer:
Embryo sac.

Question 3.
Ovule derives nourishment from which part of the carpel?
Answer:
Ovule derives nourishment from placenta.

Question 4.
What are cleistogamous flowers ? Give an example.
Answer:
The flowers which do not open are called cleistogamous flowers, e.g. Commelina

Question 5.
What is the substance found on the exine of pollen grains?
Answer:
Sparopollenin.

Question 6.
Give the characters of wind pollinated flowers.
Answer:
White in colour, small in size and pollengrains are formed in large number.

Question 7.
What is the ploidy of angiospermic endosperm?
Answer:
Triploid.

Question 8.
Give an example of a monocotyledonous endospermic seed.
Answer:
Ricinus.

Question 9.
Give example of two false fruit.
Answer:
Apple, Jackfruit.

Question 10.
What are monocious plants?
Answer:
Plants which has both male and female flower.

Sexual Reproduction in Flowering Plants Short Answer Type Questions

Question 1.
What is parthenogenesis ?
Answer:
Parthenogenesis : It is the method of reproduction in which ovum develops into embryo and forms a new plant without fertilization. It has been observed that pollination is necessary for parthenogenesis. It stimulates the process. Ulothrix, Spirogyra and Solan- aceae and Malvaceae family plants reproduce by this method.
Sometimes in some plants ovary also develops into fruit during this process. Such fruits are called as parthenocarpic fruits.
Example: Banana, Apple, Grapes, Guava etc. shows parthenocarpic fruits.

Question 2.
What is Polyembryony?
Answer:
Polyembryony : When more than one embryo develops in one seed then this condition is called as Polyembryony. It is generally found in citrus family. It is also found in Nicotiana, conifers, rice, wheat. It occurs when fertilization occurs in all embryo sacs found in the ovule.

Question 3.
Describe structure of anther with labelled diagram.
Answer:
Structure of Anther : Transverse section of anther shows that it consists of 2 lobes which are connected by connective. Each lobe contains two Pollen sacs. Innermost layer of pollen sac is called as Tapetum.

Tapetum is a layer rich in nutritive contents which supplies food material for the developing pollen grains. At first many Pollen mother cells are formed in them which divides meiotically to form haploid pollen grains.

Question 4.
Give four contrivances for self pollination.
Answer:
Contrivances for self-pollination:
(1) Bisexuality : When male and female parts are found in same flower then possibility of self-pollination increases.

(2) Cieistogamy : In Commelina benghalensis both cleistogamous and chasmogamous flowers are produced. The former are the underground flowers and the latter are the aerial ones developed on branches. In the small, inconspicuous cleistogamous flowers the pollen are shed within the closed flowers so that self-pollination is a must. This is also observed in Impatiens, Oxalis, Viola, Portulaca etc.

(3) Homogamy : Here the stamens and carpels mature at the same time. So, there is a greater chance of self-pollination as compared to cross-pollination, e.g., Mirabilis, Argemone etc.

(4) Failure of cross pollination : In some flowers generally cross pollination occurs but if they fails to do cross pollination then self-pollination occurs.

Question 5.
What do you mean by micropropagation?
Answer:
Micropropagation : It is a modern method of reproduction. By this process thousands of new plants can be obtained from few tissues of mother plant. This method is based on tissue and cell culture technique.
In this process a small part of tissue is separated from the plant and then it is grown in nutrient medium in aseptic condition. The tissue develops to form a cluster of cells which is called as callus. This callus can be preserved for long time for multiplication. A small part of the callus is transferred to nutrient medium, where it grows into a new plant. This plant is then transferred to the field. By this process Orchids, Carnations, Chrysanthemum plants can be grown successfully.

Question 6.
What are the advantages of cross-pollination ?
Answer:
Advantages of cross-pollination:

• The weaker characteristics of the race elimi¬nated and replaced by better character of nature.
• New improved varieties cap be produced by cross-pollination. ‘
• It increases the adaptability of the offsprings.
• Seeds are more vigorous.

Question 7.
What is fertilization? Draw labelled diagram showing path of pollen tube during fertilization.
Or
What do you mean by sexual reproduction? Describe the process of fertilization in plants with the help of diagram or sexual reproduction.
Answer:
Fertilization : The process of fusion of male and female gamete is called as fertilization or sexual reproduction. As a result of this process a diploid zygote is formed.

Question 8.
Differences between self and cross pollination
Answer:
Differences between Self and Cross poltination :

No.	Self pollination	Cross pollination
1.	It is the process of transfer of pollen grains from one flower to the stigma of same flower of same plant.	Transfer of pollen grains from one flower to the stigma of flower of another plant.
2.	Medium is not reqired	Medium is required
3.	Plants do not show any special chara cter.	Attractive, coloured,scent or honey bearing flowers are produced to attract insect.
4.	Less number of pollen grains are produced.	More number of pollen grains are produced.

Sexual Reproduction in Flowering Plants Long Answer Type Questions

Question 1.
What is self-pollination ? Give advantages and disadvantages of self pollination.
Answer:
Self-pollination : When the pollen grain of one flower are transferred to the stigma of the same flower then the process is called as self-pollination.

Advantages of self-pollination:
These are the advantages of self pollination:

• Parental characters can be preserved indefinitely in several generations.
• Self-pollination helps in maintaining pure lines for experimental hybridization.
• It is most economical method of pollination. The plants do not consume their energies in the production of
• large number of pollen grains, nectar and coloured corolla.
• It ensures seed production and flowers do not take chances of the failure of fertilization.

Disadvantages of self-pollination:
These are the disadvantages of self-pollination :

• The weaker characteristics or defects of the plant can never be eliminated from the race.
• No useful characters can be introduced in the race.
• The immunity of race towards diseases falls and ultimately it falls prey to many diseases.

Question 2.
What is double fertilization?
Or
Explain double fertilization in angiosperms.
Answer:
Double fertilization : It is found in all angiospermic plants. It was first discovered by S.N. Navaschin (1899) in Lilium and Fritillaria. When pollen tube come in contact of embryo sac then the tip of the pollen tube disintegrate and release two male gametes into the embryo sac. Out of which one male gamete (x) fuses with egg cell (x) to form a diploid zygote. This process is called as fertilization. The second male gamete (x) fuses with secondary nuclei (2x) to form a triploid body.
The act of two nuclear fusion is called as double fertilization.

Question 3.
Describe development of embryo sac or Female gametophyte in angiosperms.
Answer:
Development of embryo sac or Female gametophyte in angiosperms :
During the initial stage of development of ovule primary archesporial cell gets demarcated at the apex of the nucellus below the epidermis. It divides periclinally into a outer primary parietal cell or primary wall cell and an inner primary sporogenous cell. The later acts as a megaspore mother cell which enlarges in size and divide meiotically to form a row of four megaspores. Of the four cells the upper three cells degenerate and appear as dark caps while the lowest one functions arid is called the functional megaspore. The latter greatly enlarges and forms the embryo sac.

Question 4.
Describe development of Endosperm.
Answer:
Development of Endosperm : It develops from the triploid tissue of the fertilized embryo sac after the act of double fertilization. It is of the following three types:

1. Free nuclear endosperm.
2. Cellular type of endosperm.
3. Helobial type of endosperm.

The name refers to the type of nuclear divisions of the endosperm nucleus. If triploid nucleus divides by free nuclear division the endosperm produced contains many nuclei lying freely in it and hence it is termed as free nuclear endosperm. If the nuclear division is followed by wall formation it is called as cellular type. If endosperm is intermediate between the two types it is called as helobial type.


Question 5.
What is male gametogenesis ? Describe male gametogenesis in plants.
Or
Describe development of pollen grain.
Answer:
Male gametogenesis: The process of formation of male gametes is called as male gametogenesis or microsporogenesis.

Each anther usually consists of two lobes, connected together by a connective. Each lobe contains two sacs called as Pollen sac. In the early stage of development the anther comprises of a homogenous mass of cells limited by a well demarcated epidermis. During the course of development the anther gets four lobed. Each lobe exhibits a hypodermal lining, few cells thick with distinct nuclei. These hypodermal cells constitute the archesporium. The cell of archesporium divide periclinally, cutting of parietal cells towards the periphery and sporogenous cells within it two chambers or loculi, which are termed as pollen sacs or microsporangia.

Fig. Development of Pollen grain : (A) Formation of Pollen lobes, (B) Archesporial cell, (C) and (D) Division in Parietal cell, (E) and (F) Parietal layer : Tapetum sporogenous tissue (G), (H) and (I) Pollen mother cell, (J) Pollen grain, (K) Outer layer Degenerate, (L) Four free Pollen grains.

Besides the above changes in the wall layers the sporogenous layer comprising of primary sporogenous cells also undergo several divisions to form microspore mother cells or pollen mother cells. In the initial stage the microspore mother cells are closely packed but as the anther enlarges the pollen sac becomes spacious and the pollen mother cells assume spherical shape and get loosely arranged.

In many cases some of the sporogenous cells are nonfunctional and serve only as the nutritive material for the functional microspore mother cells. Each microspore mother cell is diploid in nature and by a single meiotic division give rise to four haploid nuclei. The four nuclei so formed are arranged tetrahedrally, and called as Tetrad. Innermost layer of pollen sac is called as Tapetum. Outer to which endothecium layer is formed. In outer most layer of pollen sac epidermis is formed. Surrounding each nuclei exine and intine are formed, now each structure is called as Pollen grain. Pollen grains are liberated during the dehiscence of anthers through stomium.

Question 6.
Differenciate between:
(i) Embryo sac and Endosperm
(ii) Seed and Ovule
Answer:
(i) Difference between Embryosac and Endosperm:

No.	Embryo sac	Endosperm
1.	It is haploid structure.	It is triploid structure.
2.	It is found in ovule.	It is found in seed.
3.	It is formed before fertilization.	It is formed after fertilization.
4.	Nutritive materials are stored.	Nutritive materials are not stored.
5.	It consists antipodal cells, egg cell, synergid cells and two polar nuclei.	Antipodal cells, egg cell, synergid cells are absent and all cells are similar.

(ii) Difference between Seed and Ovule

No.	Seed	Ovule
1.	It is formed in the fruit seed is formed after fertilization of ovule.	Before fertilization ovule is found into the ovary called mega sporangium.
2.	Seed is surrounded by integument. Outer covering is called outer integument and inner covering is called inner integument.	Nucellus is present below the ovule and is surrounded by inner and outer covering.
3.	Embryosac is absent in seed.	Embryosac is present in ovule.
4.	Embryo is present in seed	Embryo is absent in ovule.
5.	Endosperm may be found in seed	Endosperm is not found in ovule.
6.	Seed make a new plant	Ovule is not germinate.

MP Board Class 12th Biology Solutions

MP Board Class 9th General English Grammar Reporting

अंग्रेजी में किसी के कहे हुए वचन को दो प्रकार से प्रकट कर सकते हैं

(1) यदि किसी व्यक्ति के वही शब्द लिखे जाएँ जो उसने कहे हैं और उनमें किसी प्रकार की तब्दीली न की जाए तो उसे Direct Speech कहते हैं। जैसे

Rama said, “She is a good girl.”
यहाँ बोलने वाले के ठीक-ठीक वही शब्द दिए गए हैं।

Direct Speech
में निम्न बातों का ध्यान रखना चाहिए

(a) बोलने वाले के असली शब्दों को inverted commas (“…”) में लिखते हैं।
(b) बोलने वाले के असली शब्दों को Reported Speech कहते हैं।
(c) जो Verb (क्रिया) ‘Reported Speech’ के सम्बन्ध में कुछ बताता है उसे Reporting verb कहते हैं।

(2) जब हम बोलने वाले के असली शब्दों का प्रयोग नहीं करते परन्तु उनका तात्पर्य या अर्थ लिखते हैं तो उसे Indirect Speech कहते हैं जैसे
Rama said that she was a good girl.
Indirect speech में निम्न बातों का ध्यान रखना चाहिए

Rama said that she was a good girl.
Indirect speech में निम्न बातों का ध्यान रखना चाहिए

(a) इसमें कोई inverted commas नहीं होते। बोलने वाले के ठीक वही शब्द नहीं लिखे जाते। उनमें कुछ परिवर्तन किया जाता है।
(b) Reporting verb के बाद कोई comma नहीं लगाया जाता।
(c) Reported Speech À ved Conjunction that का प्रयोग होता है।
(d) Reported speech की क्रिया को बदलते हैं।
जब हम Direct speech को Indirect speech में बदलते हैं तो अग्रांकित बातों का ध्यान रखते हैं;

जैसे-

(1) Said को told में बदल देते हैं। Persons में परिवर्तन निम्न रूप में करते हैं।
I person के Pronoun (I, we, us, our) का परिवर्तन Direct Speech के Subject (कर्ता) के Person के अनुसार होता है II Person के Pronoun (You, Your) का परिवर्तन Object के अनुसार होता है तथ III Person के Pronoun (he, she, it, her) में कोई भी परिवर्तन नहीं होता है

(2) निकटता प्रकट करने वाले शब्दों में परिवर्तन निम्नलिखित रूप से किया जाता है-

• Now – then
• This – that
• Ago – before
• Tonight – that night
• Last night – the previous night
• Here – there
• these – those
• A year ago – a year before
• Today – that day
• Tomorrow – the next day
• Yesterday – the day before
• Just – then
• Come here – go there
• Next week – the following week

(3) Tense (काल) परिवर्तन-
(a) Reporting Verb के Present या Future Tense में होने पर Reported verb के Tense में कोई परिवर्तन नहीं होता।

(b) Reporting verb के Past Tense में होने पर Reported Verb के Tense में परिवर्तन होता है-

(i) Simple Present का Simple Past हो जाता है।
He said, “She works hard.”
He said that she worked hard.

(ii) Present Continuous का Past Continuous हो जाता है जैसे-
He said, “She is reading a book.”
He said that she was reading a book.

(iii) Present Perfect का Past Perfect हो जाता है

जैसे-
Hema said, “Ram has done his work”.
Hema said that Ram had done his work.

(iv) Present Perfect Continuous का Past Perfect Continuous हो जाता है जैसे-
Shyam said, “Ram has been working for two hours.”
Shyam said that Ram had been working for two hours.

(v) Simple Past का Past Perfect हो जाता है।

जैसे-
Sita said, “Rita read a book.”
Sita said that Rita had read a book.

(vi) Past Continuous का Past Perfect Continuous हो जाता है।

जैसे-
“Gopal said, “Govind was singing a song.”
Gopal said that Govind had been singing a song.

Shall का should, may का might, can का could हो जाता है तथ सदा सत्य व् ऐतिहासिक ताद्यों का नहीं बदलता

(1) Interrogative Sentences
Direct-Rahul said to Rama, “Is it easy to ride a bicycle ?”
Indirect-Rahul asked Rama if it was easy to ride a bicycle.
Direct—The bird said to the Prince, “Why are you weeping?”
Indirect—The bird asked the Prince why he was weeping.

Commands and Orders
Direct—Father said, “Get some milk.”
Indirect—Father told him to get some milk.
Direct—Hari said to me, “Please help me.”
Indirect—Hari requested me to help him.

Statements…

Exercise-1

Change into indirect speech.
1. Hari Babu said, “This porter carries the luggage with great care.”
2. The doctor said, “The patient does not take medicine.”
3. He said, “The man has been talking for a long time.”
4. She said, “I am drawing a picture.”
5. Pratap said, “I have fought a long battle.”
6. You said to me, “I gave you my pen.”
7. You said, “I was not saving money.”
Answer:
1. Hari Babu said that that porter carried the luggage with great care.
2. The doctor said, that the patient did not take medicine.
3. He said that the man had been talking for a long time.
4. She said that she was drawing a picture.
5. Pratap said that he had fought a long battle.
6. You told me that you had given me your pen.
7. You said that you had not been saving money.

(2) Interrogative Sentences

Exercise-2

Change into indirect speech.
1. My father said to me, “Are you going to Kanpur today?”
2. He said to me, “Do you go to cinema very often ?”
3. His brother said to me, “Was Gopal sitting on the bench ?”
4. Mr. Gupta said to me, “Will you take me too with you ?”
5. The guest said to the boy, “Did you see this film ?”
Answer:
1. My father asked me if I was going to Kanpur that day.
2. He asked me if I went to cinema often.
3. His brother asked me whether Gopal had been sitting on the bench.
4. Mr. Gupta asked me if I would take him too with me.
5. The guest asked the boy whether he had seen that film.

(3) Imperative Sentences (Commands and Requests)

Exercise-3
Change into indirect speech.
1. The old man said to the boy, “Get out of the room.”
2. He said to me, “Please do it first.”
3. I said to him, “Don’t open the box.”
4. The clergyman said to him, “May God recover you soon.”
5. She said to me, “How clever you are !”
6. The actor said, “What a beautiful scene it is !”
7. They said, “Alas ! Our beloved leader is departed !”
Answer:
1. The old man ordered the boy to get out of the room.
2. He requested me to do it first.
3. I asked him not to open the box.
4. The clergyman wished that God might recover him soon… !
5. She exclaimed with admiration that I am very clever.
6. The actor exclaimed with joy that the scene was very beautiful.
7. They exclaimed with grief that their beloved leader was departed.

MP Board Class 9th English Solutions

MP Board Class 9th General English Grammar Passive Voice

अंग्रेजी भाषा में दो प्रकार की voice होती हैंActive and Passive Voice

We drink milk. (Active voice)
हम दूध पीते हैं।

Milk is drunk by us.” (Passive voice)
दूध हमारे द्वारा पिया जाता है।

मुख्य बातें-
(1) केवल कर्म (object) वाले वाक्यों को Passive voice में बदला जा सकता है। बिना कर्म वाले वाक्यों को Passive voice में नहीं बदला जा सकता है।

जैसे-
He sleeps. Radha is weeping.
इन वाक्यों में object नहीं है इसलिए इन्हें Passive में नहीं बदला जा सकता है।

(2) Perfect Continuous वाक्यों को Passive वाक्यों में नहीं बदला जाता है

जैसे-
She has been waiting for me.

(3) Future Continuous वाक्यों को Passive वाक्यों में वाक्यों में नहीं बदला जाता है

जैसे
-I shall be going to Delhi.

(4) Passive Voice में Past participle (Third form of the verb) का प्रयोग होता है
I sing a song. (Active)
A song is sung by me.b (Passive)

Tenses Change of Voice
Continuous Tenses

(1) Present Continuous Tense Active Voice
Structure-Subject-am/is/are (not) verb + ing-object etc.
(i) Are they borrowing money?
(ii) His brother is earning a lot of money.

Passive Voice
(i) Is money being borrowed by them?
(ii) A lot of money is being earned by his brother?

Exercise-1

Change into Passive Voice :
[Structure-Object-am/is/are + being + verb III (other words) by subject]

1. Seema is cutting fruits.
2. The gardner is plucking dead leaves.
3. I am sending a parcel to Rohan.
4. The shopkeeper is selling rice.
5. Are they reading books?
Answer:
1. Fruits are being cut by Seema.
2. Dead leaves are being plucked by the gardener.
3. Rohan is being sent a parcel by me.
4. Rice is being sold by the shopkeeper.
5. Are books being read by them.

(2) Past Continuous Tense

Active Voice
Structure_Subject—was/were + verb + ing object etc. :

(i) He was singing a song.
(ii) She was not writing essays.
(iii) You were throwing balls.

Passive Voice
Structure-Object—was/were + being verb III form (other words by subject).

(i) A song was being sung by him.
(ii) Essays were not being written by her.
(iii) Balls were being thrown by you.

Exercise-2
Change into Passive Voice :
Structure-Object–was/were + being + verb III (other words) by subject.

1. His sister was knitting a sweater.
2.Why was she keeping plates into the Almirah?
3. I was learning Mathematics.
Answer:
1. A sweater was being knitted by his sister.
2. Why were plates being kept by her in the almirah?
3. Mathematics was being learnt by me.

(3) Future Continuous Tense
इस Tense की Passive Voice नहीं होती,यह सिर्फ Active Voice में ही लिखा जाता है

Indefinite Tenses

(1) Present Indefinite Tense

Active Voice
(i) You catch fish.
(ii) Sunita dries clothes.

Passive Voice
(i) Fish is caught by you.
(ii) Clothes are dried by Sunita.

Exercise-3

Change into Passive Voice :
Structure-am/is/are (not) verb III form… by subject.

1. We supply hardware material.
2. You sell standard goods.
3. She does not cut fruits.
4. Do you lend money?
5. Where do you send the parcels?
Answer:
1. Hardware material is supplied by us..
2. Standard goods are sold by you.
3. Fruits are not cut by her.
4. Is money lent by you?
5. Where are parcels sent by you?

(2) Past Indefinite Tense

Active Voice
(i) I broke the glass.
(ii) You knew me.

Passive Voice
(i) The glass was broken by me.
(ii) I was known to you.

Exercise-4

Change into Passive Voice : Structure-was/were + verb III by subject.

1. They did not bring pens.
2. Did she clean the rooms?
3. How many pens did she buy?
4. Ravi wrote a letter to Shyam.
Answer:
1. Pens were not brought by them.
2. Were rooms cleaned by her?
3. How many pens were brought by her?
4. A letter was written to Shyam by Ravi.

(3) Future Indefinite Tense

Active Voice
(i) We shall see the match.
(ii) The boys will play the match.

Passive Voice
(i) The match will be seen by us.
(ii) Match will be played by the boys.

Exercise-5

Change into Passive Voice :
1. Will you omit five questions?
2. My work will satisfy you.
3. Your brother will buy a clock.
4. My mother will look after you.
Answer:
1. Will five questions be omitted by you.
2. You will be satisfied with my work.
3. A clock will be bought by your brother.
4. You will be looked after by my mother.

Perfect Tenses
(1) Present Perfect Tense

Active Voice
(i) I have done the work.
(ii) She has spent the money.

Passive Voice
(i) The work has been done by me.
(ii) All the money has been spent by her.

Exercise-6

Change into Passive Voice :
Structure-has/have + been + verb III form by subject.

1. She has lost her purse.
2. The officer has signed the papers.
3. We have smelt the flowers.
4. You have paid the fees.
5. The students have prepared the essays.
Answer:
1. Her purse has been lost.
2. The papers have been signed by the officer.
3. The flowers have been smelt by us.
4. The fees has been paid by you.
5. The essays have been prepared by the students.

(2) Past Perfect Tense

Active Voice :
(i) Seema had drunk the tea.
(ii) The police had arrested the thief.

Passive Voice
(i) The tea had been drunk by Seema.
(ii) The thief had been arrested by the police.

Exercise-7

Change into Passive Voice :
StructureObject—had been + verb III form by subject.

1. The girls had collected the dresses.
2. They had not finished the work.
3. Had they invited us?
4. I had found my bag.
Answer:
1. The dresses had been collected by the girls.
2. The work had not been finished by them.
3. Had we been invited by them?
4. My bag had been found by me.

(3) Future Perfect Tense

Active Voice
(i) The girl will have taken tea.
(ii) She will have mentioned my name.

Passive Voice
(i) Tea will have been taken by the girl.
(ii) My name will have been mentioned by her.

Exercise-8

Change into Passive Voice :
Structure-Object—shall/will + have been verb III by subject.

1. He will have called me.
2. The guard will have blown the whistle.
3. You shall have done the work.
Answer:
1. I will have been called by him.
2. The whistle will have been blown by the guard.
3. The work shall have been done by you.

Imperative Sentences

Active Voice
(i) Buy some wool.
(ii) Do not think this.

Passive Voice
(i) Let some wool be bought.
(ii) Let this not be thought.

Exercise-9

Change into Passive Voice : Structure-Let + object + be + verb III form.
1. Forget all your sorrows.
2. Never tell lies.
3. Do not spend all the money.
Answer:
1. Let all your sorrows be forgotten.
2. Let lies never be told.
3. Let all the money not be spent.

Exercise-10

Change the following sentences into Passive Voice.
1. We killed a cobra.
2. Will you deliver the letters?
3. You please me.
4. The fisherman caught a fish.
5. Ram will speak the truth.
6. Sita kills a snake.
7. Hari did the work.
8. She is singing a song.
9. One should keep one’s promise.
10. Open the door.
Answer:
1. A cobra was killed by us.
2. Will the letters be delivered by you?
3. I am pleased with you.
4. A fish was caught by the fisherman.
5. The truth will be spoken by Ram.
6. A snake is killed by Sita.
7. The work was done by Hari.
8. A song is being sung by her.
9. One’s promise should be kept.
10. Let the door be opened.

MP Board Class 9th English Solutions

MP Board Class 9th General English Grammar Tenses

परिभाषा- The tense of a verb shows the time of an event or action of a verb.

Verb के tense से किसी घटना या कार्य के समय का ज्ञान होता है।

अंग्रेजी में Tense तीन प्रकार के होते हैं-
(i) Present tense
(ii) Past tense
(iii) Future tense.

(i) Present Tense (वर्तमान काल)—इस Tense से यह पता चलता है कि कार्य अब या अभी हुआ है। जैसे
I go to school.
(मैं स्कूल जाता हूँ।)

(ii) Past Tense (भूतकाल)—इस Tense से यह पता चलता है कि कार्य बीते हुए समय में हुआ है। जैसे
I went to school.
(मैं स्कूल गया।)

(iii) Future Tense (भविष्य काल)—इस Tense से यह पता चलता है कि कार्य आने वाले समय में होगा। जैसे
I shall go to school.
(मैं स्कूल जाऊँगा।)

प्रत्येक Tense निम्नलिखित चार प्रकार का होता है
1. Indefinite,
2. Continuous,
3. Perfect;
4. Perfect Continuous.

Present Tense (वर्तमान काल)
(1) Present Indefinite Tense-इस Tense में सदा सत्य बातें, आदतें अथवा बार-बार होने वाले कार्यों का वर्णन किया जाता है। जैसे

(i) The sun rises in the east.
सूर्य पूर्व में उदय होता है।

(ii) I go to school.
मैं स्कूल जाता हूँ।

पहचान-हिन्दी में वाक्यों के अन्त में ता, ती, ते तथा हैं, हूँ, हो होता है।
Structure -Subject + I form of verb + s, es, ies + object.

Like :
(i) Ram calls Mohan.
(ii) I eat guavas daily.

Exercise-1

Rewrite the following using correct form of the verb given in the brackets.
1. Shyam ………….. up at 6’0 clock. (get/gets)
2. They………. football in summers. (play/plays)
3. Geeta ……………. Physics from Mohan. (study/studies)
4. The sun …………….. in the east. (rise/rises)
5. One of you ………….. with me. (come/comes)
Answer:
1. gets,
2. play,
3. studies,
4. rises,
5. come.

Making the Verb Emphatic or Strong
इस tense में do या does सहायक क्रिया + I form of __verb से verb को emphatic या strong बनाया जाता है। अगर वाक्य में verb की I form है तो केवल do जोड़ा जाता है व verb की I form के साथ s, es, ies जुड़ा हो तो does जोड़कर verb में से s, es, ies हटा दिया जाता है।

Making Negative Emphatic Verb
Negative बनाने के लिए subject के बाद do not या does not + verb की I form प्रयोग करते हैं।

जैसे-
(i) I do not eat potatoes.
(ii) She does not speak French.

Exercise-2

Rewrite the following in negative form.
1. Sohan eats bananas.
2. Kamla goes to school.
3. We drink milk.
4. Mala dries clothes.
5. Each one of them works hard.
Answer:
1. Sohan does not eat bananas.
2. Kamla does not go to school.
3. We do not drink milk.
4. Mala does not dry clothes.
5. Each one of them does not work hard.

Making the Interrogative form—
Interrogative बनाने के लिये Do/Does का sentence के प्रारम्भ में प्रयोग करते हैं व अन्त में प्रश्नवाचक चिह्न लगाते हैं। जैसे-
(i) Do you play hockey?
(ii) Does she bring coffee?

Exercise-3

Rewrite the following sentences into interrogative.
1. She sings songs.
2. I speak the truth.
3. She calls her parents.
4. Sunita and Ram read well.
5. Cats drink milk.
Answer:
1. Does she sing songs?
2. Do I speak the truth?
3. Does she call her parents?
4. Do Sunita and Ram read well?
5. Do cats drink milk?

(2). Present Continuous Tense
इस Tense chat प्रयोग तब किया जाता है जब कार्य अभी भी चल रहा हो; जैसे
I am writing a letter.
मैं पत्र लिख रहा हूँ।

पहचान-हिन्दी में वाक्यों के अन्त में रहा हूँ, रहा है, रही है, रहे हैं होता है।

Structure—Subject + am/is/are Verb + ing + object etc. Negative ha fet am/is/are o are not STIRI GIAI. Subject + am/is/are + not verb + ing + object.

☆ Interrogative बनाने के लिए-
Am/Is/Are + Subject (not) verb + ing + object.

Exercise-1

Write the following sentences in Present Continuous Form. 1. You …….. the bicycle. (ride)
2. I ……. a pen. (buy)
3. She ……… a letter. (write)
4. They ……. T.V. (watch)
5. Anita ……… late for school. (get)
Answer:
1. are riding,
2. am buying,
3. is writing,
4. are watching,
5. is getting.

Exercise-2

Make the sentences negative.
1. She is cutting the vegetables.
2. Radha is going to the shop.
3. Meena is working hard for the examinations.
4. I am calling you.
Answer:
1. She is not cutting the vegetables.
2. Radha is not going to the shop.
3. Meena is not working hard for the examinations.
4. I am not calling you.

Exercise-3

Make following sentences interrogative.
1. He is not walking quickly.
2. Mala is writing carefully.
3. People in India are living peacefully.
Answer:
1. Is he not walking quickly?
2. Is Mala writing carefully?
3. Are people in India living peacefully?

(3) Present Perfect Tense-इस Tense of im ऐसे कार्य के लिए होता है जो वर्तमान में पूरा हो चुका है।
जैसे-
(i) I have done my work.
मैंने अपना काम कर लिया है।

(ii) He was written a letter.
वह एक पत्र लिख चुका है।

इसमें I, You तथा बहुवचन के साथ have तथ एकवचन के साथ has का प्रयोग किया जाता है इसमें verb की III form का ही प्रयोग होता है।

पहचान-हिन्दी में वाक्यों के अन्त में किया है, दिया है, चुका है, चुके हैं, चुका हूँ आदि होता है।

Structure-subject + has/have + verb III form | (past participle) + object

Negative बनाने के लिए have/has के बाद not का प्रयोग होता है।
Interrogative बनाने के लिए Have/Has को sentence के प्रारम्भ में subject से पूर्व प्रयोग किया जाता है।

Exercise-1

Fill in the blanks with the correct form of the verb.
1. I ……… the bell. (ring)
2. Seema ……… her work. (begin)
3. People ……… on him. (shout)
4. They ……… the shop. (close)
Answer:
1. have rung,
2. has begun,
3. have shouted,
4. have closed.

(4) Present Perfect Continuous Tense- इस Tense में कार्य पहले से हो रहा है तथा वर्तमान में भी जारी है। जैसे-

(i) I have been writing a letter for an hour.
मैं एक घण्टे से पत्र लिख रहा हूँ।

(ii) It has been raining since morning.
सुबह से वर्षा हो रही है।

इस Tense में subject के अनुसार has been या have been तथा मुख्य क्रिया में ing लगाते हैं। समय के लिए for या since का प्रयोग होता है।

Structure-subject + have been/has been + verb + ing + object-since/for time.

Exercise-1

Fill the following sentences in the Present Perfect Continuous Tense.
1. She ……… (write) a book ……… yesterday.
2. He ……… (play) the game ……… an hour.
3. The mob ……… (revolt) ……… years.
Answer:
1. has been writing, since,
2. has been playing, for,
3. has been revolting, since.

MP Board Class 9th English Solutions

MP Board Class 11th Maths Solutions Chapter 10 सरल रेखाएँ Ex 10.2

प्रश्न 1 से 8 तक रेखा का समीकरण ज्ञात कीजिए जो दिए गए प्रतिबंधों को संतुष्ट करता है।
प्रश्न 1.
x- अक्ष और y- अक्ष के समीकरण लिखिए।
हल:
x- अक्ष का समीकरण y = 0.
तथा y- अक्ष का समीकरण x = 0.

प्रश्न 2.
ढाल \(\frac{1}{2}\) और बिन्दु (- 4, 3) से जाने वाली।
हल:
ढाल m = \(\frac{1}{2}\) , बिन्दु (- 4, 3)
अभीष्ट रेखा का समीकरण
y – y₁ = m(x – x₁)
y – 3 = \(\frac{1}{2}\) = (x + 4)
या 2y – 6 = x + 4
∴ x – 2y + 10 = 0.

प्रश्न 3.
बिन्दु (0, 0) से जाने वाली और ढाल m वाली।
हल:
दिया है : बिन्दु (0, 0), ढाल = m
ढाल m, तथा (x₁, y₁) से जाने वाली रेखा का समीकरण
y – y₁ = m(x – x₁)
∴ y – 0 = m(x – 0)
अतः अभीष्ट समीकरण y = mx.

प्रश्न 4.
बिन्दु (2, 2\(\sqrt{3}\)) से जाने वाली और x-अक्ष से 75° के कोण पर झुकी हुई।
हल:
चूँकि रेखा x-अक्ष के साथ 75° पर झुकी हुई है, तब रेखा की ढाल
m = tan 75° = tan (45° + 30°)

या (2 + \(\sqrt{3}\))x – y + 2\(\sqrt{3}\) – 4 – 2\(\sqrt{3}\) = 0
अतः (2 + \(\sqrt{3}\))x – y – 4 = 0.

प्रश्न 5.
मूल बिन्दु के बाईं ओर x- अक्ष को 3 इकाई की दूरी पर प्रतिच्छेद करने तथा ढाल – 2 वाली।
हल:
मूल बिन्दु से बाईं ओर 3 इकाई की दूरी पर स्थित बिन्दु (- 3, 0) होगा तथा ढाल m = – 2
m तथा (x₁, y₁) के द्वारा रेखा का समीकरण,
y – y₁ = m(x – x₁)
वहाँ x₁ = – 3 तथा y₁ = 0 रखने पर,
y – 0 = – 2(x + 3)
या y = – 2x – 6
या 2x + y + 6 = 0.

प्रश्न 6.
मूल बिन्दु से ऊपर y-अक्ष को 2 इकाई की दूरी पर प्रतिच्छेद करने वाली और x-अक्ष की धन दिशा के साथ 30° का कोण बनाने वाली।
हल:
मूल बिन्दु से y-अक्ष पर 2 इकाई की दूरी पर स्थित बिन्दु (0, 2) होगा। x-अक्ष की धन दिशा के साथ रेखा 30° का कोण बनाती है।
∴ m = tan 30° = \(\frac{1}{\sqrt{3}}\)
रेखा का समीकरण,
y – y₁ = m (x – x₁)
y – 2 = \(\frac{1}{\sqrt{3}}\) (x – 0)
या \(\sqrt{3}\)y – 2\(\sqrt{3}\) = x
या x – \(\sqrt{3}\)y + 2\(\sqrt{3}\) = 0.

प्रश्न 7.
बिन्दुओं (-1, 1) और (2 – 4) से जाते हुए।
हल:

या 3y – 3 = – 5x – 5
अतः 5x + 3y + 2 = 0.

प्रश्न 8.
उस रेखा का समीकरण ज्ञात कीजिए जिसकी मूल बिन्दु से लांबिक दूरी 5 इकाई और लंब धन x-अक्ष से 30° का कोण बनाती है।
हल:
हम जानते हैं कि लंब रूप में रेखा AB का समीकरण,
x cos ω + y sinω = P
यहाँ पर दिया है: ω = 30°, तथा p = 5

∴ रेखा AB का समीकरण,
x cos 30 + y sin 30 = 5
x.\(\frac{\sqrt{3}}{2}\) + y.\(\frac{1}{2}\) = 5
∴ \(\sqrt{3}\)x + y = 10.

प्रश्न 9.
∆PQR के शीर्ष P(2, 1), Q(- 2, 3) और R(4, 5) हैं। शीर्ष R से जाने वाली माध्यिका का समीकरण ज्ञात कीजिए।
हल:
PQ का मध्य बिन्दु अर्थात् m (0, 2) है।
∴ दो बिन्दुओं से जाने वाली रेखा का समीकरण,

अब बिन्दुओं R (4, 5) तथा M(0, 2) से जाने वाली रेखा का समीकरण,
y – 5 = \(\frac{2-5}{0-4}\) = (x – 4)
या 4(y – 5) = 3 (x – 4)
या 3x – 4y + 8 = 0
अतः माध्यिका RM का समीकरण 3x – 4y + 8 = 0.

प्रश्न 10.
(- 3, 5) से होकर जाने वाली और बिन्दु (2, 5) और (- 3, 6) से जाने वाली रेखा पर लंब रेखा का समीकरण ज्ञात कीजिए।
हल:
बिन्दु A(2, 5) और B(- 3, 6) से होकर जाने वाली रेखा का ढाल

यदि PL बिन्दु P(- 3, 5) से AB पर लम्ब डाला गया हो तो उसकी ढाल m₂ मान लीजिए।
रेखाएँ PL और AB परस्पर लम्ब हैं।
यदि PL की ढाल × AB की ढाल = – 1
अर्थात m₂ × \(\left(-\frac{1}{5}\right)\) = – 1
∴ m₂ = 5
PL की ढाल 5 है और P(- 3, 5) से होकर जाती है तो PL का समीकरण,
y – y₁ = m₂(x – x₁)
या y – 5 = 5 (x + 3)
∴ 5x – y + 20 = 0.

प्रश्न 11.
एक रेखा (1, 0) तथा (2, 3) बिन्दुओं को मिलाने वाली रेखाखंड पर लम्ब है तथा उसको 1 : n के अनुपात में विभाजित करती है। रेखा का समीकरण ज्ञात कीजिए।
हल:
रेखा AB बिन्दु A(1, 0) तथा B(2, 3) से होकर जाती है।
∴ AB की ढाल = \(\frac{3-0}{2-1}=\frac{3}{1}\)
PQ ⊥ AB
AB की ढाल = \(\frac{3}{1}\)

∴ PQ की ढाल, m = \(-\frac{1}{\frac{3}{1}}=-\frac{1}{3}\)
PQ रेखा AB को C पर प्रतिछेदन करती है।
साथ ही बिन्दु C रेखाखंड AB को 1 : n के अनुपात में बांटता है।

या (n + 1)x + 3(n + 1)y = n + 2 + 9 = n + 11
या (n+ 1) x + 3 (n + 1)y = n + 11.

प्रश्न 12.
एक रेखा का समीकरण ज्ञात कीजिए जो निर्देशांक अक्षों से समान अंत:खण्ड काटती है और बिन्दु (2, 3) से जाती है।
हल:
(i) रेखा AB बिन्दु P(2, 3) से होकर जाती है और निर्देशांक अक्षों पर समान अंत: खंड बनाती है।
OA = OB
∠BAO = 45°,
∠BAX = 135°

AB की ढाल, m = tan 135° = – 1
रेखा का समीकरण, y – y₁ = m(x – x₁)
जहाँ x₁ = 2, Y₁ = 3 तथा m = – 1
y – 3 = – (x – 2)
या x + y – 5 = 0
या x + y = 5.

प्रश्न 13.
बिन्दु (2, 2) से जाने वाली रेखा का समीकरण ज्ञात कीजिए जिसके द्वारा अक्षों से कटे अंतःखंडों का योग 9 है।
हल:
मान लीजिए P(2, 2) से होकर जाने वाली रेखा से अक्षों पर बने अंतः खंड a तथा b हैं।

अंतः खंड रूप में रेखा का समीकरण
\(\frac{x}{a}+\frac{y}{b}\) = 1
यह रेखा P(2, 2) से होकर जाती है।
∴ \(\frac{2}{a}+\frac{2}{b}\) = 1
दिया है कि अंतः खंडों का योग 9 है।
∴ a + b = 9
b = 9 – a
b का मान (1) में रखने पर,
\(\frac{2}{a}+\frac{2}{9-a}\) = 1
या 2(9 – a) + 2a = a (9 – a)
18 – 2a + 2a = 9a – a₂
या a₂ – 9a + 18 = 0
या (a – 6)(a – 3) = 0
a = 6, 3
b = 3, 6
जब a = 6 तथा b = 3 हो, तो रेखा का अभीष्ट समीकरण
\(\frac{x}{6}+\frac{y}{3}\) = 1
या 3x + 6y = 18
या x + 2y = 6.
जब a = 3 तथा b = 6 हो, तब रेखा का अभीष्ट समीकरण,
\(\frac{x}{3}+\frac{y}{6}\) = 1
या 6x + 3y = 18
या 2x + y = 6

प्रश्न 14.
बिन्दु (0, 2) से जाने वाली और धन x-अक्ष से \(\frac{2 \pi}{3}\) के कोण बनाने वाली रेखा का समीकरण ज्ञात कीजिए। इसके समांतर और y-अक्ष को मूल बिन्दु से 2 इकाई नीचे की दूरी पर प्रतिच्छेद करती हुई रेखा का समीकरण भी ज्ञात करो।
हल:
माना एक रेखा PQ बिन्दु P(0, 2) से होकर जाती है और धन x-अक्ष के साथ \(\frac{2 \pi}{3}\) का कोण बनाती है।
∴ PQ की ढाल = tan\(\frac{2 \pi}{3}\)
= – \(\sqrt{3}\)

∴ रेखा PQ का समीकरण, y – y₁ = m(x – x₁ )
y – 2 = – \(\sqrt{3}\) (x – 0)
या \(\sqrt{3}\)x + y – 2 = 0.
दूसरी रेखा RS रेखा PQ के समांतर है
∴ RS का ढाल = –\(\sqrt{3}\)
यह रेखा (0, – 2) से होकर जाती है।
रेखा RS का समीकरण, y – y₁ = m(x – x₁)
y + 2 = –\(\sqrt{3}\) (x – 0)
\(\sqrt{3}\)x + y + 2 = 0.

प्रश्न 15.
मूल बिन्दु से किसी रेखा पर डाला गया लम्ब रेखा से बिन्दु (- 2, 9) पर मिलता है। रेखा का समीकरण ज्ञात कीजिए।
हल:
मान लीजिए रेखा AB पर मूल बिन्दु से डाला गया लम्ब AB पर मिलता है।
OP की ढाल = – \(\frac{y_{2}-y_{1}}{x_{2}-x_{1}}\)
= \(\frac{9-0}{-2-0}=-\frac{9}{2}\)
परन्तु AB ⊥ OP

अब AB की ढाल \(\frac{2}{9}\) है और P(- 2, 9) से होकर जाती है।
∴ AB का समीकरण
y – y₁ = m(x – x₁)
अर्थात् y – 9 = \(\frac{2}{9}\) = (x + 2) या
या 9y – 81 = 2x +4
या 2x – 9y + 85 = 0.

प्रश्न 16.
तांबे की छड़ की लम्बाई L (सेमी में) सेल्सियस ताप C का रैखिक फलन है। एक प्रयोग में यदि L= 124.942, जब C = 20 और L= 125.134 जब C = 110 हो, तो L को C के पदों में व्यक्त कीजिए।
हल:
L ताप C का रैखिक फलन है।
(20, 124.942), (110, 125.134) इसका रैखिक फलन है। इन दो बिन्दुओं से संतुष्ट फलन

प्रश्न 17.
किसी दूध भण्डार का स्वामी प्रति सप्ताह 980 लीटर दूध, 14 रू प्रति लीटर के भाव से और 1220 लीटर दूध 16 रू प्रति लीटर के भाव से बेच सकता है। विक्रय मूल्य तथा मांग के मध्य के संबंध को रैखिक मानते हुए ज्ञात कीजिए कि प्रति सप्ताह वह कितना दूध 17 रू प्रति लीटर के भाव से बेच सकता है?
हल:
दूध के भाव और मात्रा में रैखिक सम्बन्ध है। यह रेखा दो बिन्दुओं (14, 980), (16, 1220) से होकर जाती है।
इससे प्राप्त रेखा का समीकरण,
y – y₁ = \(\frac{y_{2}-y_{1}}{x_{2}-x_{1}}\) (x – x₁)
y – 980 = \(\frac{1220-980}{16-14}\)(x – 14)
= \(\frac{240}{2}\)(x – 14)
= 120(x – 14)
y = 980 + 120 (x – 14)
जब x का मान 17 है तो y का मान नीचे दिया गया है।
y = 980 + 120(17 – 14)
= 980 + 120 × 3
= 980 + 360
= 1340
अतः 17 रू प्रति लीटर भाव का 1340 लीटर दूध बिकेगा।

प्रश्न 18.
अक्षों के बीच रेखाखंड का मध्य बिंदु P(a, b) है। दिखाइए कि रेखा का समीकरण \(\frac{x}{a}+\frac{y}{b}\) = 2 हैं।
P(a, b)
हल:
माना रेखा AB अक्षों पर p और q अंतःखंड बनते हैं।
∴ बिन्दु A और B के क्रमशः निर्देशांक (p, 0) और (0, q) हैं।

प्रश्न 19.
अक्षों के बीच रेखाखण्ड को बिन्दु R(h, k), 1 : 2 के अनुपात में विभक्त करता है। रेखा का समीकरण ज्ञात कीजिए।
हल:
अक्षों के बीच रेखाखंड AB को R(h, k) AR : RB = 1 : 2 के अनुपात में विभक्त करता है।
मान लीजिए अक्षों पर अंत:खण्ड OA = a और OB = b है।

a और b के मान रखने पर,
\(\frac{x}{\frac{3 h}{2}}+\frac{y}{3 k}\) = 1
या \(\frac{2 x}{h}+\frac{y}{k}\) = 3
या 2kx + hy = 3hk.

प्रश्न 20.
रेखा के समीकरण की संकल्पना का प्रयोग करते हुए सिद्ध कीजिए कि तीन बिन्दु (3, 0), (-2,-2) और (8, 2) संरेख हैं।
हल:
बिन्दु A(3, 0), B(- 2, – 2) से होकर जाने वाली रेखा का समीकरण

बिन्दु C(8, 2) इस रेखा पर पड़ता है तब इसके निर्देशांक इस समीकरण को संतुष्ट करेंगे।
∴ 2 × 8 – 5 × 2 – 6 = 0
या 16 – 16 = 0
अतः दिए हुए बिन्दु A, B, C सरेख हैं।

MP Board Class 11th Maths Solutions

MP Board Class 9th General English Grammar Subject-Verb Concord

किसी sentence में जब subject का verb के साथ सही तालमेल होता है तभी वाक्य शुद्ध होता है। अर्थात् subject के वचन (number) तथा पुरुष (Person) के अनुसार ही verb में आवश्यक परिवर्तन किया जाना चाहिए।

जैसे-
Bird is flying in the sky.
Birds are flying in the sky.
I was singing
They were singing.

इस प्रकार के तालमेल के लिए निम्नलिखित नियम हैं
(1) दो या उससे अधिक Singular subject and से जोड़े जाएँ तो उनके साथ प्रायः Plural का verb आता है। जैसे
(i) Sita and Gita are twins.
(ii) You and your sister do this job well.

(2) यदि दो singular nouns (संज्ञाएँ) एक ही व्यक्ति या वस्तु का बोध कराती हैं, तो वहाँ singular verb का प्रयोग होता है। जैसे
(i) You and I am wrong.
(ii) My brother and guide has come.

(3) अगर singular कर्ता से पहले Each या Every का प्रयोग होता है तो singular verb का प्रयोग होता है। जैसे
(i) Every day brings hope.
(ii) Each student is prepared.

(4) Either….or, neither…..nor, के बाद हमेशा singular verb आती है। जैसे-
(i) Neither is he happy nor sad.
(ii) Either Ram or Shyam has done this work.

(5) यदि कर्ता को or, nor से जोड़ा जाए और वचन भिन्न हो तो बहुवचन की क्रिया (verb) का प्रयोग होता है। जैसे
(i) Either the boy or his friends have done this.

(6) Collective Noun के साथ पूरे समूह का भाव व्यक्त करने के लिए एकवचन क्रिया (verb) का प्रयोग करते हैं। परन्तु अगर एकवचन क्रिया का बोध कराना हो तो Plural verb का प्रयोग करते हैं। जैसे
(i) The police were chasing the thief.
(ii) The committee has decided this.

(7) जो Noun देखने में बहुवचन लगते हैं पर भाव में एकवचन ही होते हैं उनके साथ singular verb का प्रयोग करते हैं। जैसे
The wages of sin is death.

(8) कुछ Noun देखने में Singular लगते हैं परन्तु उनका अर्थ Plural होता है। उनके साथ Plural verb का प्रयोग करते हैं। जैसे
People are sad.

(9) कभी-कभी हम Verb का निकटतम Plural Subject के साथ मेल कर देते हैं। इस तरह वास्तविक subject की अनदेखी हो जाती है। हमें इस गलती से सावधान रहना चाहिए। जैसे-
(i) Neither of the women was present.
(ii) The quality of the oranges was good.

(10) Plural Noun जो किसी देश का नाम है या किताब का नाम है उसके बाद singular verb का प्रयोग होता है। जैसे
(i) The United States has a strong army.
(ii) The Gathering is a good novel.

Exercise-1

Fill in the blanks with correct words from those in brackets.
1. No news …………………….. bad news. (is/are)
2. The meeting …………………….. chosen a president. (has/have)
3. Each of the suspected men …………………….. been interrogated. (has/have)
4. Rice and curry …………………….. his favorite dish. (is/are)
5. All work and no play …………………….. Jack a dull boy. (make/makes)
Answer:
1. is,
2. has,
3. has,
4. are,
5. makes.

Exercise-2

Correct the following sentences.
1. Ten thousand rupees are a good sum.
2. Bread and butter are my food.
3. He and not you deserve this reward.
4. This pair of scissors are sharp.
5. Either you or your brother have done this.
6. The jury were of one mind.
7. None of them are rotten.
8. He as well as his parents are illiterate.
9. The king and poet are here.
10. Your spectacles is dirty.
Answer:
1. Ten thousand rupees is a good sum.
2. Bread and butter is my food.
3. He and not you deserve this reward.
4. This pair of scissors is sharp.
5. Either you or your brother has done this.
6. The jury was of one mind.
7. None of them is rotten.
8. He as well as his parents is illiterate.
9. The king and poet is here.
10. Your spectacles are dirty.

MP Board Class 9th English Solutions