CBSE Class 12

NCERT Solutions for Class 12 Biology Chapter 2 Sexual Reproduction in Flowering Plants

These Solutions are part of NCERT Solutions for Class 12 Biology. Here we have given NCERT Solutions for Class 12 Biology Chapter 2 Sexual Reproduction in Flowering Plants

Question 1.
Name the parts of an angiosperm flower in which development of male and female gametophyte take place.
Solution:
Inside the anther, the cells of microsporangia develop as male gamete. Inside the ovary megasporangial cells develop as female gametes.

Question 2.
Differentiate between microsporogenesis and megasporogenesis. Which type of cell division occurs during these events? Name the structures formed at the end of these two events.
Solution:
Differences between microsporogenesis and megasporogenesis are as follows :

During microsporogenesis and Megas-megasporogenesis meiotic cell division occurs which results in haploid gametes – the microspores or pollen grains and megaspores.

Question 3.
Arrange the following terms in- the correct developmental sequence : Pollen grain, sporogenous tissue, microspore tetrad, pollen mother cell, male gametes.
Solution:
Sporogenous tissue → Pollen mother cell → microspore tetrad → pollen grain → male gamete.

Question 4.
With a neat, labelled diagram, describe the parts of a typical angiosperm ovule.

Solution:
An angiosperm ovule consists of the following parts:

• The ovule is attached to placenta by means of a stalk called funicle or funiculus.
• The point of attachment of funiculus to the body of ovule is called hilum.
• The main body of ovule is made of parenchymatous tissue called nucellus.
• Nucellus is covered on its outside by one or two coverings called integuments and hence ovule is rightly called as integument megasporangium.
• The integuments cover entire nucellus except for a small pore at upper end, which is called the micropyle. Micropyle is formed generally by inner integument or by both integuments.
• The place of junction of integuments and nucellus is called chalaza.
• In inverted ovules (most common type), the stalk or funiculus is attached to the main body of ovule for some distance to form a ridge like structure, called- raphe.
• In the nucellus of ovule, a large oval cell is present at micropylar end, which is known as embryo sac (female gametophyte), which develops from the megaspore.

Question 5.
What is meant by monosporic development of female gametophyte?
Solution:
The female gametophyte or the embryo sac develops, from a single functional megaspore. This is known as the monosporic development of the female gametophyte. In most flowering plants, a single megaspore mother cell present at the micropylar pole of the nucellus region of the ovule undergoes meiosis to produce four haploid megaspores. Later out of these 4 megaspores, only one functional megaspore develops into a female gametophyte, while the remaining 3 degenerates.

Question 6.
With a neat diagram explain the 7-celled, 8 nucleate nature of the female gametophyte
Solution:

The female gametophyte (embryo sac) develops from a single functional megaspore. Thus, the megaspore undergoes three successive mitotic divisions to form 8 nucleate embryo sac. The first mitotic division in the megaspore forms 2 nuclei. One nucleus moves towards the micropylar end while the other nucleus moves towards the chalazal end. Then these nuclei divide at their respective ends and redivide to form 8 nucleate stages.

As a result there are 4 nuclei each at both the ends i.e., at the micropylar and the chalazal end in the embryo sac. At the micropylar end, out of 4 nuclei only 3 differentiate into 2 synergids and one egg cell. Together they are known as egg apparatus. Similarly, at the chalazal end 3 out of 4 nuclei differentiates as antipodal cells. The remaining 2 cells (of the micropylar and chalazal end) move towards the centre and are known as the polar nuclei, which are situated in the centre of the embryo sac. Hence, at maturity, the female gametophyte appears as a 7 celled structure, though it has 8 nucleate.

Question 7.
What are chasmogamous flowers? Can cross-pollination occur in cleistogamous flowers? Give reasons for your answer.
Solution:
Chasmogamous flowers or open flowers in which anther and stigma are exposed for pollination. Cross-pollination cannot occur in cleistogamous flowers. These flowers remain closed thus causing only self-pollination. In cleistogamous flowers, anthers dehisce inside the closed flowers. So the pollen grains come in contact with stigma. Thus there is no chance of cross¬pollination, e.g., Oxalis, Viola.

Question 8.
Mention two strategies evolved to prevent self pollination in flowers.
Solution:
Two strategies evolved to prevent self-pollination are:

• Pollen release and stigma receptivity are not synchronized.
• Anthers and stigma are placed at such positions that pollen doesn’t reach stigma.

Question 9.
What is self-incompatibility? Why does self-pollination not lead to seed formation in self-incompatible species?
Solution:
When the pollen grains of an anther do not germinate on the stigma of the same flower, then such a flower is called self-sterile or incompatible and such condition is known as self¬incompatibility or self-sterility.
The transference of pollen grains shed from the anther to the stigma of the pistil is called pollination. This transference initiate the process of seed formation. Self-pollination is the transfer of pollen grain shed from the anther to stigma of pistil in the same flower. But in some flower self¬pollination does not lead to the formation of seed formation because of the presence of same sterile gene on pistil and pollen grain.

Question 10.
What is bagging technique? How is it useful in a plant breeding programme?
Solution:
It is the covering of female plants with butter paper or polythene to avoid their contamination from foreign pollens during the breeding programme.

Question 11.
What is triple fusion? Where and how does it take place? Name the nuclei involved in triple fusion.
Solution:
Inside the embryo sac, one male gamete fuses with egg cells to form a zygote (2n) and this is called syngamy or true act of fertilisation. This result of syngamy, i.e., zygote (2n) ultimately develops into an embryo.

The second male gamete fuses with 2 polar nuclei or secondary nucleus to form triploid primary endosperm nucleus and this is called triple fusion. The result of triple fusion, i.e., primary endosperm nucleus (3n) ultimately develops into a nutritive tissue for developing embryo called endosperm.

The nuclei involved in this triple fusion are the two polar nuclei or secondary nucleus and the second male gamete.

Question 12.
Why do you think the zygote is dormant for sometime in a fertilised ovule?
Solution:
The zygote is dormant in fertilized ovule for some time because, at this time, endosperm needs to develop. As endosperm is the source of nutrition for the developing embryo, nature ensures the formation of enough endosperm tissue before starting the process of embryogenesis.

Question 13.
Differentiate between:

1. Epicotyl and hypocotyl;
2. Coleoptile and coleorhiza;
3. Integument and testa;
4. Perisperm and pericarp

Solution:

1. Differences between epicotyl and hypocotyl are as follows :
   
2.  Differences between coleoptile and coleorhiza are as follows :
   
3. Differences between integument and testa are as follows :
   
4. Differences between perisperm and pericarp are as follows :
   

Question 14.
Why is apple called a false fruit? Which part (s) of the flower forms the fruit?
Solution:
Apple is called a false fruit because it develops from the thalamus instead of the ovary (the thalamus is the enlarged structure at the base of the flower).

Question 15.
What is meant by emasculation? When and why does a plant breeder employ this technique?
Solution:
Emasculation is the removal of stamens mainly the anthers from the flower buds before their dehiscence. This is mainly done to avoid self-pollination. Emasculation is one of the measures in the artificial hybridization. Plant breeders employed this technique to prevent the pollination within same flower or to pollinate stigmas with pollens of desired variety.

Question 16.
If one can induce parthenocarpy through the application of growth substances, which fruits would you select to induce parthenocarpy and why ?
Solution:
Oranges, lemons, litchis could be potential fruits for inducing the parthenocarpy because a seedless variety of these fruits would be much appreciated by the consumers.

Question 17.
Explain the role of tapetum in the formation of pollen-grain wall.
Solution:
Tapetum is the innermost layer of the microsporangium. The tapetal cells are multinucleated and polyploid. They nourish the developing pollen grains. These cells contain ubisch bodies that help in the ornamentation of the microspores or pollen grains walls. The outer layer of the pollen grain is called exine and is made up of the sporopollenin secreted by the ubisch bodies of the tapetal cells. This compound provides spiny appearance to the exine of the pollen grains.

Question 18.
What is apomixis and what is its importance ?
Solution:
Apomixis is the process of asexual production of seeds, without fertilization.
The plants that grow from these seeds are identical to the mother plant.

Uses:

• It is a cost-effective method for producing seeds.
• It has great use for plant breeding when specific traits of a plant have to be preserved.

We hope the NCERT Solutions for Class 12 Biology Chapter 2 Sexual Reproduction in Flowering Plants help you. If you have any query regarding NCERT Solutions for Class 12 Biology Chapter 2 Sexual Reproduction in Flowering Plants, drop a comment below and we will get back to you at the earliest.

NCERT Solutions for Class 12 Biology Chapter 7 Evolution

These Solutions are part of NCERT Solutions for Class 12 Biology. Here we have given NCERT Solutions for Class 12 Biology Chapter 7 Evolution

Question 1.
Explain antibiotic resistance observed in bacteria in light of Darwinian selection theory.
Solution:
Penicillin when discovered was used as an antibiotic against all bacteria. Soon many of these became resistant. This is because alleles of resistance which are already present in bacteria are of no importance in absence of antibiotics. Adjustment to change in environment due to genetic variation is adaptation.

Question 2.
Find out from newspapers and popular science articles any new fossil discoveries or controversies about evolution.
Solution:
Chimps are more evolved than humans (The Times of India):
Chimpanzees are more evolved than humans, a study suggests. There is no doubt that humans are the more advanced species. But a comparison of 14,000 human and chimpanzee genes shows the forces of natural selection have and the greatest impact on our ape cousins.

The researchers’ discovery challenges the common assumption that our large brains and high intelligence were the gifts of natural selection. Humans and chimps followed different evolutionary paths from a common ape ancestor about 5 million years ago. Both underwent changes as the fittest survived to pass their genes on to future generations. But the US study shows that humans possess a ‘substantially smaller’ number of positively-selected genes than chimps.

Question 3.
Attempt giving a clear definition of the term species.
Solution:
A species generally includes a similar organism. Members of this group can show interbreeding. A similar group of genes are found in the members of the same species and this group has the capacity to produce new species. Every species has some cause of isolation which interrupted the interbreeding with the nearest reactional species which is referred to as reproductively isolated.

Question 4.
Try to trace the various components of human evolution (hint: brain size and function, skeletal structure, dietary preference, etc.)
Solution:
Human evolution shows the following trends:
A. Brain size: It increased gradually along with evolution. The brain capacity of Australopithecus africanus – 500 cc, Homo habilis – 700 cc, Homo eredus – 800 – 1300 cc, Homo sapiens sapiens – 1450 cc.

B. Skeletal structure:

• Dryopithecus was ape-like, without brow ridges, had semierect posture, and prognathous face (having a projecting jaw).
• Ramapithecus had jaws and teeth like humans (small canines and large molars), prognathous face, and walked on legs
• Australopithecus africanus had erect posture, human-like teeth, was without chin, with brow ridges, and had a prognathous face.
• Homo habilis walked nearly erect, had human-like teeth, with brow ridges face was slightly prognathous.
• Homo erectus had an erect posture, prognathous face, with projecting brow ridges, small canines, and large molar teeth and had a small chin.
• Homo sapiens had four curves in the vertebral column, orthognathous face (without projecting jaw), forehead broad, chin well developed, walked on the sole.

C. Dietary preference: Dryopithecus and Ram-apithecus were herbivores, Australopithecus africanus and Homo habilis were carnivores, Homo erectus and Homo sapiens were omnivores.

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

Question 6.
List 5-6 modern-day animals and using the internet resources link it to a corresponding ancient fossil. Name both.
Solution:
The list of few modern-day animals and their corresponding ancient fossils is as follows:

Question 7.
Describe one example of adaptive radiation.
Solution:
Adaptive radiation – Formation of different species from a common ancestor with new species adapting to different geological niches.
Example: Darwin’s finches are Galapagos island have wolves from mainland finches. They underwent changes in the shape, size of beaks, food habits, feathers.

Question 8.
Can we call human evolution adaptive radiation?
Solution:
No, we can not be called human evolution as adaptive evolution.

Question 9.
Using various resources such as your school library or the Internet and discussions with your teacher, trace the evolutionary stages of any one animal say horse.
Solution:
The evolutionary stages of the modern horse are listed in the table given below:

We hope the NCERT Solutions for Class 12 Biology Chapter 7 Evolution help you. If you have any query regarding NCERT Solutions for Class 12 Biology Chapter 7 Evolution, drop a comment below and we will get back to you at the earliest.

Here we are providing NCERT Solutions for Class 12 English Vistas Chapter 5 Should Wizard hit Mommy. Students can get Class 12 English Should Wizard hit Mommy NCERT Solutions, Questions and Answers designed by subject expert teachers.

Should Wizard hit Mommy NCERT Solutions for Class 12 English Vistas Chapter 5

Should Wizard hit Mommy NCERT Text Book Questions and Answers

Should Wizard hit Mommy Reading with insight

Question 1.
What is the moral issue that the story raises?
Answer:
The characters in Jack’s stories held the narrator’s views that he had derived from personal experience. Telling the story to his daughter, Jo, Jack tried to encourage moral good. The characters react according to values based on his personal conviction.
In Roger Skunk’s story, the skunk smelt so bad that none of the other little creatures would play with him. With the skunk’s disgrace, Jack recalled his own humiliation as a child. The wizard granted Roger Skunk his wish and soon he smelt of roses. He found friends as a consequence of changing himself, but his mother felt that he smelt awful. She took him back to that “awful wizard”, and made the wizard change Roger back.

When Jo felt that Roger Skunk’s mommy was stupid, Jack emphatically defended her. He argued that the little skunk loved his mommy more than he loved all the other little animals and believed that his mommy knew what was right. Through his story, evidently, Jack reiterated the fact that parents know what is best for their children and advocates unquestioning obedience in the children.

Question 2.
How does Jo want the story to end? Why?
Answer:
Jo, like any normal child, wanted the story to have a happy ending. She did not want the skunk to be shunned by his friends for a lifetime. She was happy when the skunk smelt of roses and gained acceptability. So, she could not bear the fact that Roger Skunk’s mommy felt that a skunk should smell like one and had him changed back.

Jo was sorry for the skunk who had been insulted by the other creatures for such a long time. She wanted to change the end of the story. She wanted the wizard to hit the skunk’s mommy on the head and not change the little skunk back into a foul-smelling creature.

Question 3.
Why does Jack insist that it was the wizard that was hit and not the mother?
Answer:
Jo’s insistence that the wizard should hit mommy back, angered Jack. Jack insisted that it was the wizard that was hit and not the mother because every time Jack created a story, he laced it with some autobiographical details. Roger Skunk’s insult was based on his own childhood—he remembered “certain humiliations” of his own. Jack felt he was telling her “something true, something she must know”. Thus, when Roger Skunk’s mommy found the smell of roses awful, she took him back to the wizard.

She hit the wizard right over the head with an umbrella and made him change his smell. When Jo insisted the wizard hit mommy, Jack refused to do so. Evidently, he had been taught by his own mother to embrace his individuality at the cost of popularity. He wished to pass on the moral to his daughter in the garb of a simple story. With “rare emphasis” Jack defended the mommy as if “he was defending his own mother to her”. He refused to alter the end and insisted that the little skunk loved his mommy more than he loved all the other little animals and she knew what was right for him.

Question 4.
What makes Jack feel caught in an ugly middle position?
Answer:
Jack continued telling the story even when he heard Clare moving around heavy furniture though she was six months pregnant. After Jack finished the story, he went downstairs. He saw his wife, Clare wearing an old shirt of his on top of her maternity dress, painting the chair.
He thought of the woodwork as confining as a cage and felt himself caught in an ugly middle position.

This is a representation in fiction of the way in which the male psyche is reinforced by the patriarchal cultural climate of the 1950s that began to unravel during the 1960s and 1970s. The unsettling of gender roles and perspectives is further reflected in the story. The male chauvinistic attitude was reflected even while he was telling the story to his daughter. When Jo thought the story was over, jack resented her attitude. He did not like women when they took anything for granted. He liked them apprehensive, hanging on to his words.

Question 5.
What is your stance regarding the two endings to the Roger Skunk story?
Answer:
Agreeing with the end of Jo’s story:

• Poetic justice—good rewarded
• Tiny skunk was innocent so it was unfair to punish him
• The skunk had found friends after a long time
• Being isolated and humiliated is not good for a child’s psyche
• Mommy needed to sympathise with Roger Skunk’s emotion

Agreeing with the end of Jack’s story:

• The world is based on individual differences
• One has to be true to one’s identity
• Parents are a better judge of the situation
• Life has to be accepted in totality in all its colours

Question 6.
Why is an adult’s perspective different from that of a child?
Answer:
An adult’s perspective is different from that of a child’s because

• children have a rose-tinted view of the world while adults are more realistic, even cynical.
• duty, morals, individuality, etc. are terms that children realise later in life.
• children understand only the reality that they have been exposed to and cannot think of ideas and feelings in abstraction.
• children understand only basic emotions such as happiness and sadness.
• children cannot justify or explain an unhappy ending.

Should Wizard hit Mommy Extra Questions and Answers

Should Wizard hit Mommy Short Answer Questions

Question 1.
How did Jo respond to her father’s story-telling?
Answer:
Jo listened to her father’s stories with interest and looked forward to the ritual. However, Jack felt that working his way through this routine was especially tiring on Saturday, because Jo never fell asleep any more. Jo patiently listened to the story and at times predicted the happy end with delight.

Question 2.
What similarity did Jack view in Roger Skunk and himself?
Answer:
The tiny little Roger Skunk smelt very bad. None of the other little woodland creatures agreed to play with him. He was alienated by his peers and he was left alone in tears. Jack’s empathy with the creature revealed that he had faced humiliations of a similar nature in his own childhood. He identified with the plight of Roger Skunk.

Question 3.
How did the Wizard help the skunk?
Answer:
The Wizard rummaged around for his magic wand and asked Roger Skunk what he wanted to smell like. Roger replied that he wished to smell like roses. The skunk’s wish was fulfilled. He was pleased with his transformation and was happy to have friends to play with.

Question 4.
How did Roger Skunk find the extra pennies?
Answer:
The Wizard asked the skunk to go to the end of the lane and turn around three times and look down the magic well and there he would find three pennies.

Question 5.
What had upset Jo about the Skunk’s story? How did Jack react to it?
Answer:
Roger Skunk’s mother felt that Roger should smell like a little skunk and not like roses. She took Roger Skunk back to that wizard and hit him right over his head with an umbrella and made him change Roger back. This upset Jo, she wanted the wizard to hit Mommy back and refuse to change Roger back. Jo’s . reaction upset Jack. He tried to make her see how Roger Skunk’s mother knew what was best for Roger.

Question 6.
What story did Jo want to hear the next day? Why? What was the father’s reaction?
Answer:
Jo pleaded with Jack to continue with the same story, the next day, where the wizard hit Roger’s mommy back with the magic wand. Being a child, she looked forward to a happy ending and could identify with the seclusion of the skunk. But Jack refused, he wanted the little skunk to listen to what his mommy thought was best for him. He reasoned with Jo that Roger loved his mother more than all the other little animals, and she knew what was right for him.

Should Wizard hit Mommy Long Answer Questions

Question 1.
Jack had a typical pattern of story that he told Jo. What was the pattern?
Answer:
The characters in Jack’s stories were based on his personal experiences. Through the stories that he told his daughter Jo, Jack tried to encourage goodness and decency. The animal characters in each story, a small creature, usually named Roger (Roger Fish, Roger Squirrel, Roger Chipmunk), reacted according to values based on personal conviction. The character had some problem and went with it to the wise old owl. In Roger Skunk’s story, the skunk smelt so bad that none of the other little creatures would play with him.

The owl told him to go to the wizard, and the wizard performed a magic spell that solved the problem. The wizard would then demand in payment more pennies than that Roger Creature had, but he would direct the animal to a place where the money could be found. Then Roger would be happy and play many games with other creatures, and go home to his mother just in time to hear the train whistle that brought his daddy home from Boston and they would have a sumptuous meal.

Question 2.
What was Roger Skunk’s problem? How was it resolved?
Answer:
In Roger Skunk’s story, Roger Skunk smelt very bad. It was because of his foul smell none of the other little creatures would play with him. Tiny animals called him Roger “Stinky Skunk” which made him miserable.He could do nothing but cry. The owl suggested that Roger Skunk meet the wizard. He told Roger that to go there the skunk needed to go through the dark woods, under the apple trees, into the swamp, over the crick to the wizard’s house. The wizard granted Roger Skunk his wish and soon he smelt of roses. He found friends with his new smell but his mother felt that he smelt awful. She took him back to that “awful wizard”, hit him on his head and the wizard made Roger Skunk smell bad again.

When Jo felt that Roger Skunk’s mommy was stupid, Jack emphatically defended her. He argued that the little skunk loved his mommy more than he loved all the other little animals and believed that his mommy knew what was right. Through his story, evidently, Jack reiterated the fact that parents know what is best for their children and advocates the unquestioning obedience of the children.

Question 3.
Why was Roger Skunk’s mommy not happy with the change in her child? What did she do?
Answer:
When Roger Skunk went to the wizard and told him he had no friends because of his foul smell, the wizard with his magical powers changed Roger Skunk’s foul smell to a very pleasant one. When Roger Skunk ran out into the woods, smelling of roses, all the other animals gathered around him because he smelled so good: But Roger Skunk’s mommy felt that he smelt awful. She took Roger Skunk to the wizard and hit him over his head with an umbrella. She made the wizard make Roger Skunk smell very bad again. After Daddy Skunk came home from Boston they had a sumptuous meal and mommy hugged Roger Skunk and said he smelled like her baby.

Question 4.
Why was Jo not happy with end of story? Why did her father not agree with her?
Answer:
Jo, like any other child, wanted the story to have a happy ending. She did not want the skunk to be rejected by his friends. She was happy when the skunk smelt of roses and was accepted by his friends. As a result she could not bear the fact that Roger Skunk’s mommy felt that a skunk should smell like one and she hit the wizard over the head, who in turn made Roger Skunk smell very bad again.

Jo felt sorry for the skunk who had been insulted by the other creatures for smelling bad. It was for the first time . that he had found company of his friends. Therefore, in order to change the end of the story, she wanted the wizard to hit the skunk’s mommy on the head and not change the little skunk back into a foul-smelling creature.

Question 5.
Jack’s stories were autobiographical. Justify this statement with reference to the skunk’s story.
Answer:
Jack created the stories out of his mind. Therefore, the stories were bound to have some autobiographical details. The story of Roger Skunk who smelled so bad that none of the other little woodland creatures would play with him was out of his own childhood. He remembered “certain humiliations of his own”. He evoked Jo’s pity by tracing Roger Skunk’s tears along the side of her nose. Jack felt he was telling her “something true, something she must know”.

Thus, when Roger Skunk’s mommy found the smell of roses awful, she took him back to the wizard. She hit the wizard right over the head with an umbrella and made him change his smell to the original one. When Jo insisted the wizard hit mommy, Jack retorted sharply. With “rare emphasis”, Jack defended the mommy as if “he was defending his own mother to her”. He was not willing to alter the end of the story and insisted that the little skunk loved his mommy more than he loved all the other little animals, since she knew what was right for him.

Question 6.
The story depicts Jack’s tension based on his perception of gender roles. Give reasons to justify your answer.
Answer:
While Jack was telling the story, he heard sounds of furniture being moved but he did not go down to help Clare, though he knew that she should not move heavy things as she was six months pregnant. After Jack finished the story, he went downstairs and saw his wife, Clare wearing an old shirt of his on top of her maternity dress, painting the chair. He visualized the woodwork as a cage and he felt caught in an ugly middle position.

He felt that both of them were caged together. He did not want to speak with her, work with her or touch her. This is a representation in fiction of the way in which the male psyche is reinforced by the patriarchal cultural climate of the 1950s that began to unravel during the 1960s and 1970s. This unsettling of gender roles and perspectives is further reflected in the story. The male chauvinistic attitude was reflected even while he was telling the story to his daughter, Jo, who assumed the story to be over. But, Jack did not like women when they took anything for granted; he liked them apprehensive, hanging on his words. Thus, he deliberately contained them in his story.

Question 7.
The story within a story is dealt with very convincingly. Justify.
Answer:
Jack narrated the story of Roger Skunk to Jo. The story effectively brings out Jack’s emotions and the child’s perspective. Jack creates a story out of his mind with autobiographical details. In Roger Skunk’s isolation, he recalls “certain humiliations of his own”. He wishes Jo to know “something true”, something she must know “and has (had) no wish to hurry on”. Jack wishes her to realize that the skunk’s mommy loves him very much. She knows what is right for him. He defends the skunk’s mommy from Jo’s allegation of her being stupid, with rare emphasis, as though he was defending his own mother to her.

With Jo, on the other hand, Updike successfully brings out the child’s perspective. She has learnt about a new creature, a skunk, at nursery school, and wants him as the hero of her bedtime story. Her joy and sorrow is linked to that of the protagonist, the skunk. She does not want to dwell on his sorrow. On the contrary, she wants him to get over his troubles quickly and wishes for the story to have a happy ending. She expresses her emotions, likes and dislikes immediately, like any other four-year-old. She longs for the story to end on an optimistic note—“that the wizard took that magic wand and hit that mommy”.

Question 8.
What is your stance regarding the two endings to Roger Skunk’s story?
Answer:
The end of Jo’s story ensures poetic justice—where good is rewarded. Roger Skunk was innocent and having him suffer comes across as unjust. The skunk had found friends after long. Being isolated and humiliated is not good for a child’s psyche. It is important that his mommy understood his need for acceptance amongst his peers. The end of Jack’s story gives out that the world is based on individual differences. One has to be true to one’s identity. Parents are better judge of the situation. One should accept of life in all its colours.

Question 9.
There is a hint of marital discord in the story. Justify.
Answer:
Certain threads in the story, which come up, like digressions from time to time hint at the marital discord between Jack and his wife. When Jack heard a chair scrape downstairs, he realized his wife was at work but he “had no wish to hurry on”. He made a dispirited observation of Jo’s expression “without a trace of sincerity” and was reminded of his wife’s feigning pleasure at cocktail parties. He continued with the story, leaving his pregnant wife to move around heavy furniture.

After the story, Jack went downstairs and watched his wife labour, but did not help her. He felt “caught in an ugly middle position” and must have felt trapped in responsibility and marriage. The use of the image of the “cage” while reveals his dissatisfaction with his marriage. The story ends with the most poignant and telling lines—“…he did not want to speak with her, work with her, touch her, anything”.

NCERT Solutions for Class 12 Biology Chapter 13 Organisms and Populations

These Solutions are part of NCERT Solutions for Class 12 Biology. Here we have given NCERT Solutions for Class 12 Biology Chapter 13 Organisms and Populations

Question 1.
How is diapause different from hibernation ?
Solution:
Diapause is different from hibernation. The table below shows the differences between them :

Question 2.
If a marine fish is placed in a freshwater aquarium/will the fish be able to survive? Why or why not?
Solution:
If a marine fish is placed in a freshwater aquarium, then its chances of survival will diminish. This is because their bodies are adapted to high salt concentrations in the marine environment. In freshwater conditions, they are unable to regulate the water entering the body (through osmosis). Water enters their body due to the hypotonic environment outside. This results in the swelling up of the body, eventually leading to the death of the marine fish.

Question 3.
Define phenotypic adaptation. Give one example.
Solution:
Phenotypic adaptation involves non-genetic changes in individuals such as physiological modifications like acclimatization or behavioural changes.

Question 4.
Most living organisms cannot survive at temperatures above 45°C. How are some microbes able to live in habitats with temperatures exceeding 100°C?
Solution:
organisms survive at a temperature range of 0° to 40°C or less. However, there are some notable exceptions. Certain microorganisms live in hot springs and deep-sea hydrothermal vents where temperature far exceeds 100°C. They survive at the high temperature due to the occurrence of branched-chain lipids in their cell membrane that reduces the fluidity of cell membranes and the occurrence of the minimum amount of free water in their cells that provides resistance to high temperature

Question 5.
List the attributes that populations but not individuals possess.
Solution:

1. Natality
2. Mortality
3. Growth forms
4. Population density
5. Population dispersion
6. Population age distribution

Question 6.
If a population growing exponentially double in size in 3 years, what is the intrinsic rate of increase (r) of the population?
Solution:
The intrinsic rate of increase(r), can be calculated by the following exponential growth equation:

Question 7.
Name important defence mechanisms in plants against herbivory.
Solution:

1. Modification of leaves into thorns.
2. Development of spiny margins on leaves.
3. Development of sharp silicated edges on leaves.

Question 8.
An orchid plant is growing on the branch of the mango tree. How do you describe this interaction between the orchid and the mango tree?
Solution:
An orchid growing as an epiphyte on a branch of mango tree is an example of commensalism. Commensalism is the relationship between individuals of two species of which one is benefited and the other is almost unaffected, i.e., neither benefited nor harmed. A commensal may get shelter (protection), or ride, or support instead of or in addition to food. Epiphytes are space parasites, they use trees only for attachment and manufacture their own food by photosynthesis. In Vanda, an epiphytic orchid, a special kind of aerial roots (hanging roots) hang freely in the air and absorb moisture with the help of their special absorptive tissue called velamen.

Question 9.
What is the ecological principle behind the biological control method of managing pest insects?
Solution:
Predation is the means of biological control to manage pest insects where predators prey upon pests and regulate their numbers in the habitat.

Question 10.
Distinguish between the following:

1. Hibernation and Aestivation
2. Ectotherms and Endotherms

Solution:

1. Differences between hibernation and aestivation are as follows :
   
2. Differences between ectotherms and endotherms are as follows:
   

Question 11.
Write a short note on :
(a) Adaptations of desert plants and animals
(b) Adaptations of plants to water scarcity
(c) Behavioral adaptations in animals
(d) Importance of light to plants
(e) Effect of temperature or water scarcity and the adaptations of animals.
Solution:
a. Desert plants are called xerophytes. They have adaptations for increased water absorption, reduction in transpiration and water storage. Many desert plants have a thick cuticle on their leaf surfaces and have their stomata arranged in deep pits to minimise water loss through transpiration. They also have a special photosynthetic pathway that enables their stomata to remain closed during day time. In desert plants like Opuntia, leaves are reduced to spines. Animals of dry areas may use metabolic water and reduce water loss bypassing nearly solid faeces and urine.

b. Xerophytes have special adaptations to withstand prolonged periods of drought. These are of four types – ephemerals, annuals, succulents and non-succulent perennials.

• Ephemerals (drought escapers): Plants which live for a brief period and complete their life cycle during the rains.
• Annuals (drought evaders): Plants which continue to live for a few
  months even after rains in hot dry conditions. They have modifications to reduce transpiration.
• Succulents (drought resistants): Plants have fleshy organs to store large amounts of water. They have a very thick cuticle, sunken stomata which open during night only.
• Non-succulent perennials: These are true xerophytes. They have an extensive root system to absorb the maximum amount of water. They possess waxy coatings on leaves, sunken stomata, reduced leaf blades etc. to reduce transpiration.

c. The animals with variable temperatures called poikilotherms are affected by temperature variations. They are also called ectotherms. They show different adaptations like hibernation, aestivation, periodic activity, winter eggs, and migration.

d. Sun is the ultimate source of energy for most of the organisms on this earth. Light is the visible range of the electromagnetic spectrum. Light (400 nm-700nm) is effective in photosynthesis and is called photo-synthetically active radiation or PAR. The intensity of light, duration of light, etc. are also influencing the growth of plants.

e. Animals live in arid regions show two kinds of adaptations

1. Reducing loss of water from their bodies.
2. Ability to tolerate arid conditions.

Question 12.
List the various abiotic environmental factors.
Solution:
Abiotic factors are non-living factors and conditions of the environment which influence the survival, function and behaviour of organisms. Various abiotic factors are :

(i) Temperature – Temperature is one of the most important environmental factors. The average temperature varies seasonally. It ranges from subzero level in polar areas and high altitudes to more than 50°C in tropical deserts in summer and exceeds 100°C in thermal springs and deep-sea hydrothermal vents.

(ii) Water – Next to temperature, water is the most important factor which influences the life of organisms. The productivity and distribution of land plants are dependent upon the availability of water. Animals are adapted according to water availability. E.g., aquatic animals are ammonotelic while xerophytic animals excrete dry feces and concentrated urine.

(iii) Light – Plants produce food through photosynthesis for which sunlight is essential to the source of energy. Light intensity, light duration and light quality influences the number of life processes in organisms, such as – photosynthesis, growth, transpiration, germination, pigmentation, movement and photoperiodism.

(iv) Humidity – Humidity refers to the moisture (water vapour) content of the air. It determines the formation of clouds, dew and fog. It affects the land organisms by regulating the loss of water as vapour from their bodies through evaporation, perspiration and transpiration.

(v) Precipitation – Precipitation means rainfall, snow, sleet or dew. Total annual rainfall, seasonal distribution humidity of the air and amount of water retained in the soil are the main criteria that limit the distribution of plants and animals on land.

(vi) Soil – The soil is one of the most important ecological factor called the edaphic factor. It comprises of different layers called horizons. The upper weathered humus containing part of soil sustains terrestrial plant life.

Question 13.
Give an example for:

1. An endothermic animal
2. An ectothermic animal
3. An organism of the benthic zone.

Solution:

1. Hedgehog
2. Frog
3. Sponges

Question 14.
Define population and community.
Solution:
Population: A population is a group of individuals of the same species, which can reproduce among themselves and occupy a particular area in a given time.

Community: It is an assemblage of several populations in a particular area and time and exhibits interaction and interdependence through trophic relationship.

Question 15.
Define the following terms and give one example for each.
(a) Commensalism
(b) Parasitism
(c) Camouflage
(d) Mutualism
(e) Interspecific competition
Solution:

a. Commensalism is an interspecific interaction between individuals of two species where one species is benefitted and the other is not affected.
e. g. Orchid and mango tree.

b. Parasitism is an interspecific interaction between individuals of two species where generally small species is benefitted and the large species are affected, e.g. Malarial parasite and human beings.

c. Camouflage: It is the ability of the animals to blend with the surroundings or background. In this way, animals remain unnoticed for protection or aggression. An example is a stick insect.

d. Mutualism is an interspecific interaction between individuals of two species where both the interacting species are benefitted in an obligatory way. e.g. Pollination in plants by animals.

e. Interspecific competition: It is an interaction between individuals of two species where both the interacting species are affected, e.g. Monarch butterfly and Queen monarch.

Question 16.
With the help of a suitable diagram describe the logistic population growth curve.
Solution:
Logistic population growth curve or S-shaped or sigmoid growth curve is shown by the populations of most organisms. It has the following phases: lag phase, log phase, exponential phase and stationary phase. In lag phase there is little or no increase in population. In log phase increase in population starts and occurs at a slow rate in the beginning. During exponential phase, increase in population becomes rapid and soon attains its full potential rate. This is due to the constant environment, availability of food and other requirements of life in plenty, absence of predation and interspecific competition and no serious intraspecific competition so that the curve rises steeply upward. The growth rate finally slows down as environmental resistance increases.

Finally, the population becomes stable during the stationary phase because now the number of new cells produced almost equals to the number of cells that die. Every population tends to reach a number at which it becomes stabilized with the resources of its environment. A stable population is said to be in equilibrium, or at saturation level. This limit in population is a constant K and is imposed by the carrying capacity of the environment. The sigmoid growth form is represented by the following equation :

r = intrinsic rate of natural increase
N = population density at time t; K = carrying capacity.

Question 17.
Select the statement which best explains parasitism.
(a) One organism is benefited.
(b) Both the organisms are benefited
(c) One organism is benefited, other is not affected
(d) One organism is benefited, other is affected.
Solution:
(d) One organism is benefited, other is affected,

Question 18.
List any three important characteristics of a population and explain.
Solution:
The three important characteristics of a population are:

1. Birth and death rate
2. Age structure
3. Sex ratio

(i) The birth rate (natality) of a population refers to the average number of young ones produced per unit time (usually per year). In the case of humans, it is commonly expressed as the number of births per 1,000 individuals in the population per year. The death rate (mortality) of a population is the average number of individuals that die per unit time (usually per year). In humans, it is commonly expressed as the number of deaths per 1,000 persons in a population per year.

(ii) The age structure of a population is the percentage of individuals of different ages such as young, adult and old. Age structure is shown bv organisms in which individuals of more than one generation coexist. The ratio of various age groups in a population determines the current reproductive status of the population. It also indicates what may be expected in the future. The population is divided into three age groups; pre-reproductive, reproductive and post-reproductive.

(iii) The sex ratio of a population refers to the number of females per thousand male individuals. There were 933 females per 1,000 males in our country in the 2001 census. The number of females in a population is very important as it is often directly related to the number of births. The number of males may be less significant because in many species a single male can mate with several females.

We hope the NCERT Solutions for Class 12 Biology Chapter 13 Organisms and Populations help you. If you have any query regarding NCERT Solutions for Class 12 Biology Chapter 13 Organisms and Populations, drop a comment below and we will get back to you at the earliest.

NCERT Solutions for Class 12 History Chapter 9 Kings and Chronicles The Mughal Courts are part of NCERT Solutions for Class 12 History. Here we have given NCERT Solutions for Class 12 History Chapter 9 Kings and Chronicles The Mughal Courts.

NCERT Solutions for Class 12 History Chapter 9 Kings and Chronicles The Mughal Courts

Question l.
Describe the process of manuscript production in the Mughal court.
Solution :
The process of manuscript production in the Mughal court involved a variety of tasks as mentioned below :

• Paper makers prepared the folios of the manuscript.
• Scribes or calligraphers used to copy the text.
• Gliders illuminated the pages of the manuscript.
• Painters illustrated the scenes from the text to describe it in a visual form.
• Bookbinders gathered the individual folios and set them within ornamental covers.

At the end of above tasks, the finished manuscript was seen as a precious object, a work of intellectual wealth and beauty. It was an example of power of its patron, the Mughal emperor, to bring such beauty into being.

Question 2.
In what ways would the daily routine and special festivities associated with the Mughal court have conveyed a sense of the power of the emperor?
Solution :
The daily routine and special festivities associated with the Mughal court observed the following:

1. By representing the status of the court.
2. In form of salutation of emperor.
3. Jharokha Darshan.
4. Meeting held by sultan in Diwan-i-Am and Diwan-i-Khas.
5. By honouring the mansabdar on special occasion with special gifts and jagir.

Question 3.
Assess the role played by women of the imperial household in the Mughal Empire.
Solution :
The role played by women of the imperial household was significant:

1. Nur Jahan took an important part in the administration during the period of Jahangir.
2. After Nur Jahan, Mughal queens and princesses began to control significant financial resources. Shah Jahan’s daughters Jahanara and Roshanara enjoyed an annual income often equal to that of high imperial mansabdars. Jahanara, in addition, received revenues from the port city of Surat, which was a lucrative centre of overseas trade.
3. The princess Jahanara played an important role in the arrangement of marriage of Dara Shukoh and Nadira.
4. Control over resources enabled women to commission buildings and gardens. Jahanara participated in many architectural projects of Shah Jahan’s new capital, Shahjahanabad (Delhi) which included an imposing double-storeyed caravanserai with a courtyard and garden. The bazaar of Chandni Chowk was too designed by Jahanara.
5. Besides taking part in different activities, some women such as Gulbadan Begum, daughter of Babur, wrote the Humayun Nama. She was Akbar’s aunt and when Akbar commissioned Abu’l Fazl to write history of his reign, he requested her to record her memoirs of earlier times under Babur and Humayun. She described the conflicts and tensions among the princes and kings and the important mediating role elderly women of the family played in resolving some of these conflicts.

Question 4.
What were the concerns that shaped Mughal policies and attitudes towards regions outside the subcontinent ?
Solution :
The following concerns shaped Mughal policies and attitudes towards regions outside the subcontinent:

1. The Safavids and Qandahar : Qandahar was a bone of contention between the Safavids and the Mughals due to its strategic importance because all conquerors who sought to make their way into the Indian subcontinent had to cross the Hindukush to have access to north India. It was, therefore, a constant aim of Mughal policy to ward off this potential danger by controlling strategic outposts — notably Qandahar and Kabul. It was under these circumstances that the Mughals tried to have control over Qandahar. It was under the possession of Humayun but later the Mughals lost control of it. Akbar reconquered it in 1595. The Safavids, however, maintained diplomatic relations with the Mughals, but they always continued to stake claims to Qandahar. In 1622, the Persian army besieged Qandahar and defeated the Mughals. The city once again came under the control of the Safavids. Thus, due to its strategic importance Qandahar remained a bone of contention between the Mughals and the Safavids.
2. The Ottomans : Pilgrimage and trade :
   • The relationship between the Mughals and the Ottomans was to ensure free movement for merchants and pilgrims in the territories under Ottoman control, particularly in Hijaz (Ottoman Arabia) where the important centres of Mecca and Madina were located.
   • The Mughal emperors combined religion and commerce by exporting valuable merchandise to Aden and Mokha, both Red Sea ports. They distributed the proceeds of the sales in charity to the keepers of shrines and religious men there.
3. Mughals and the Portuguese : After the discovery of a direct sea route to India, the Portuguese king was interested in the propagation of Christianity with the help of missionaries. Akbar too was curious about Christianity. So, Jesuits mission came to India in 1580, 1591 and 1595. At public assemblies, Jesuits were assigned places in close proximity to Akbar’s throne.

Question 5.
Discuss the major features of Mughal provincial administration. How did the centre control the provinces?
Solution :

1. The head of the provincial administration was the governor (subadar). He reported directly to the emperor.
2. Each suba was divided into sarkar,
3. The local administration was looked after at the level of the pargana (sub-district) by three semi-hereditary officers, the qanungo (keeper of revenue records), the chaudhur (in charge of revenue collection) and the qazi.
4. Each department of administration maintained a large support staff of clerks, accountants, auditors, messengers, and other functionaries who were technically qualified officials, functioning in accordance with standardised rules and procedures, and generating copious written orders and records.

Question 6.
Discuss, with examples, the distinctive features of Mughal chronicles.
Solution :
The distinctive features of Mughal chronicles were as given below :

1. They projected a vision of enlightened kingdom to all those who were under it and conveyed a message to the resistors that they could not be successful in their objects.
2. The chronicles were commissioned by the Mughal rulers to ensure that there was an account of their rule for posterity.
3. The chronicles were written by the courtiers who focused on events centred on the ruler, his family, the court and nobles, wars and administrative arrangements because for them the history of the empire and the court was synonymous with that of the emperor. Their titles were therefore, after the name of emperors such as Akbar Naina, Shahjahan Nama and Alamgir Nama.
4. Mughal chronicles were written in Persian e.g., Akbar Nama. Babur’s memoirs was translated from the Turkish into Persian Babur Nama.
5. The chronicles were manuscripts and included paintings to enhance their beauty.
6. Chronicles showed the power of the Mughal kings came directly from God. The emperors were portrayed wearing the halo to symbolise the light of God.
7. Mughal chronicles presented the empire as compromising many different ethnic and religious communities. Abu’l Fazl described the ideal of sulh-ikul as the comer stone of enlightened rule.

Question 7.
To what extent do you think the visual material presented in this chapter corresponds with Abu’l Fazl’s description of the taswir (Source 1)?
Ans:

1. Drawing the likeness of anything is called taswir. His Majesty from his earliest youth, has shown a great predilection for this art, and gives it every encouragement, as he looks upon it as a means both of study and amusement.
2. A very large number of painters set to work.
3. Each week, several supervisors and clerks of the imperial workshop submit before the emperor the work done by each artist, and his Majesty gives a reward.
4. Paintings served not only to enhance the beauty of a book, but were believed to possess special powers of communicating ideas about the kingdom and the power of kings in ways that the written medium could not.
5. The historian Abu’l Fazl described painting as a ‘magical art’ in his view it had the power to make inanimate objects look as if they possessed life.

Question 8.
What were the distinctive features of the Mughal nobility ? How was their relationship with the emperor shaped ?
Solution :

1. The distinctive features of the Mughal nobility were as given below :
   • The nobility was recruited from diverse ethnic and religious groups. No faction was large enough to challenge the authority of the state.
   • There were Turani, Iranian, Rajputs, and Indian Muslims (Shaikhzadas).
   • Nur Jahan was an Iranian and so Iranians gained high offices under Jahangir.
   • Aurangzeb appointed Rajputs to high offices.
   • All holders of government offices held mansabs comprising two numerical designations zat and sawar.
   • The nobles participated in military campaigns with their armies. They also served as officers of the empire in the provinces.
   • Akbar established spiritual relationships with a select band of his nobility by treating them as his disciples (murid).
   • Nobles stationed at the court were a reserve force to be deputed to a province or military campaign.
2. Their relationships with the emperor were shaped in different ways :
   • As the nobility was recruited from diverse ethnic and religious groups, no faction was strong enough to challenge the authority of the state.
   • The emperor personally reviewed their rank, titles and postings.
   • Akbar maintained spiritual relationship with some nobles and treated them as the disciples.
   • The influence of different groups of nobility changed from time to time. For example, Iranians were influential in the time of Jahangir but Rajputs and Marathas became influential dining the time of Aurangzeb.
   • The emperor used to award them with office or titles to maintain their loyality towards
     him.
   • According to the Jesuit priest Father Antonio Monserrate, resident at the court of Akbar, in order to prevent the great nobles becoming insolent through the unchallenged enjoyment of power, the emperor used to summon them to court and give them imperious commands, as though they were his slaves.

Question 9.
Identify the elements that went into the making of the Mughal ideal of kingship.
Solution :
The following elements went into the making of the Mughal ideal of kingship :

1. Divine light – Court chronicles considered that the power of the Mughal kings came directly from God. Abu’l Fazl placed Mughal kingship as the highest station in the hierarchy of objects receiving light emanating from God. King was the source of spiritual guidance for his subjects. Thus, Mughal artists portrayed emperors wearing the halo to symbolise the light of God.
2. A unifying force – The emperor was source of peace and stability. He stood above all religious and ethnic groups, mediated among them, and ensured that justice and peace prevailed. Abu’l Fazl describes the ideals of sulh-i kul as the comer stone of enlightened rule. Under the sulh-i kul, the nobility of the Mughals consisted of Iranis, Turanis, Afghans, Rajputs and Deccanis — all of whom were given positions on the basis of their merits and loyalty to the king. Akbar abolished pilgrimage tax in 1563 and Jizya in 1564.
3. Just sovereignty as social contract : Under Mughal ideal of kingship, Abu’l Fazl defined sovereignty as a social contract. The emperor protected the life (jan), property (mal), honour (namus) and faith (din) of his subjects and in return demanded their obedience and a share of resources.

We hope the NCERT Solutions for Class 12 History Chapter 9 Kings and Chronicles The Mughal Courts help you. If you have any query regarding NCERT Solutions for Class 12 History Chapter 9 Kings and Chronicles The Mughal Courts, drop a comment below and we will get back to you at the earliest.