NCERT Exemplar solutions for Biology [English] Class 12 chapter 7 - Evolution [Latest edition]

Which of the following is used as an atmospheric pollution indicator?

The theory of spontaneous generation stated that ______.

Animal husbandry and plant breeding programmes are the examples of ______.

Palaeontological evidence for evolution refers to the ______.

The bones of forelimbs of whale, bat, cheetah and man are similar in structure, because ______.

Analogous organs arise due to ______.

(p + q)² = p² + 2pq + q² = 1 represents an equation used in ______. 

Appearance of antibiotic-resistant bacteria is an example of ______.

Evolution of life shows that life forms had a trend of moving from ______

Viviparity is considered to be more evolved because ______.

Fossils are generally found in ______.

For the MN-blood group system, the frequencies of M and N alleles are 0.7 and 0.3, respectively. The expected frequency of MN-blood group bearing organisms is likely to be ______.

Which type of selection explains industrial melanism observed in moth, Biston bitularia ______.

The most accepted line of descent in human evolution is ______.

Which of the following is an example for link species?

Match the scientists listed under column ‘I’ with ideas listed column ‘II.

In 1953 S. L. Miller created primitive earth conditions in the laboratory and gave experimental evidence for origin of first form of life from pre-existing non-living organic molecules. The primitive earth conditions created include ______.

Variations during mutations of meiotic recombinations are ______.

What were the characteristics of life forms that had been fossilised?

Did aquatic life forms get fossilised? If, yes where do we come across such fossils?

What are we referring to? When we say 'simple organisms' or 'complex organisms'.

How do we compute the age of a living tree?

Give an example for convergent evolution and identify the features towards which they are converging.

How do we compute the age of a fossil?

What is the most important pre-condition for adaptive radiation?

How do we compute the age of a rock?

When we talk of functional macromolecules (e.g. proteins as enzymes, hormones, receptors, antibodies etc), towards what are they evolving?

In a certain population, the frequency of three genotypes is as follows:

What is the likely frequency of B and b alleles?

Among the five factors that are known to affect Hardy-Weinberg equilibrium, three factors are gene flow, genetic drift and genetic recombination. What are the other two factors?

What is the Founder's effect?

Who among the Dryopithecus and Ramapithecus was more man-like?

By what Latin name the first hominid was known?

Among Ramapithecus, Australopithecines and Homo habilis - who probably did not eat meat?

Louis Pasteur’s experiments, if you recall, proved that life can arise from only pre-existing life. Can we correct this as life evolves from pre-existent life or otherwise we will never answer the question as to how the first forms of life arose? Comment.

The scientists believe that evolution is gradual. But extinction, part of evolutionary story, are 'sudden' and 'abrupt' and also group-specific. Comment whether a natural disaster can be the cause for extinction of species.

Why is nascent oxygen supported to be toxic to aerobic life forms?

While creation and presence of variation is directionless, natural selection is directional as it is in the context of adaptation. Comment.

The evolutionary story of moths in England during industrialisation reveals, that 'evolution is apparently reversible'. Clarify this statement.

Comment on the statement that "evolution and natural selection are end result or consequence of some other processes but themselves are not processes".

State and explain any three factors affecting allele frequency in populations.

Gene flow occurs through generations. and can occur across language barriers in humans. If we have a technique of measuring specific allele frequencies in different population of the world, can we not predict human migratory patterns in pre-history and history? Do you agree or disagree? Provide explanation to your answer.

How do you express the meaning of words like race, breed, cultivars or variety?

When we say "survival of the fittest", does it mean that

1. Those which are fit only survive, or
2. Those that survive are called fit

Comment.

Enumerate three most characteristic criteria for designating a Mendelian population.

"Migration may enhance or blurr the effects of selection". Comment.

Name the law that states that the sum of allelic frequencies in a population remains constant. What are the five factors that influence these values?

Explain divergent evolution in detail. What is the driving force behind it?

You have studied the story of Pepper moths in England. Had the industries been removed, what impact could it have on the moth population? Discuss.

What are the key concepts in the evolution theory of Darwin?

Two organisms occupying a particular geographical area (say desert) show similar adaptive strategies. Taking examples, describe the phenomenon.

We are told that evolution is a continuing phenomenon for all living things. Are humans also evolving? Justify your answer.

Had Darwin been aware of Mendel’s work, would he been able to explain the origin of variations. Discuss.