Biology

Evolution

Question:

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

Answer:

Creation and variation occur in a sexually reproducing population as a result of crossing over during meiosis and random fusion of gametes. It is however the organisms that are selected over a period of time which are determined by the environmental conditions. In other words, the environment provides the direction with respect to adaptations so that the organisms are more and more fit in terms of survival.

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Evolution

Q 1.

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?

Q 2.

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

Q 3.

By what Latin name the first hominid was known?

Q 4.

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

Q 5.

How do we compute the age of a fossil?

Q 6.

When we say "survival of the fittest", does it mean that
a. those which are fit only survive, or
b. those that survive are called fit? Comment.

Q 7.

Describe one example of adaptive radiation.

Q 8.

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

Q 9.

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?

Q 10.

How do we compute the age of.a rock?

Q 11.

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.

Q 12.

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

Q 13.

Find out from newspapers and popular science articles any new fossil discoveries or controversies about evolution.

Q 14.

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

Q 15.

Practise drawing various animals and plants.

Q 16.

Gene flow occurs through generations. Gene flow 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.

Q 17.

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

Q 18.

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

Q 19.

Attempt giving a clear definition of the term species.

Q 20.

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

Q 21.

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

Q 22.

In a certain population, the frequency of three genotypes is as follows:
Genotypes: BB, Bbbb
Frequency: 22%, 62%, 16%
What is the likely frequency of B and b alleles?

Q 23.

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.

Q 24.

List 10 modern-day animals and using the” internet resources link it to a corresponding ancient fossil. Name both.

Q 25.

How do we compute the age of a living tree?

Q 26.

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.

Q 27.

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

Q 28.

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

Q 29.

What is founder effect?

Q 30.

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

Q 31.

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

Q 32.

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

Q 33.

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

Q 34.

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

Q 35.

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

Q 36.

Find out through internet and popular science articles whether animals other than man has self-consciousness.

Q 37.

Enumerate three most characteristic criteria for designating a Mendelian population.

Q 38.

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.

Q 39.

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

Q 40.

Try to trace the various components of human evolution (hint: brain size and function, skeletal structure, dietary preference, etc.)

Q 41.

Explain antibiotic, resistance observed in bacteria in light of Darwinian selection theory.

Q 42.

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

Q 43.

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

Q 44.

Can we call human evolution as adaptive radiation?