DIRECTIONS : This question contain STATEMENT-1 (Assertion) and STATEMENT-2 (Reason) and question has 4 choices (a), (b), (c) and (d) out of which ONLY ONE is correct.
Statement 1 : Darwin’s finches show a variety of beaks suited for eating large seeds, flying insects and cactus seeds.
Statement 2 : Ancestral seed-eating stock of Darwin’s finches radiated out from South American mainland to different geographical areas of the Galapagos Islands, where they found competitor-free new habitats.
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Solution
Darwin finches are an excellent example of the way in which the species gene pools have adapted in order for long term survival via their offspring. Finches were formed due to divergent evolution (Adaptive radiation)to avoid inter specific competition.
The common birds of Galapagos islands, the finches were markedly different from the finches of main land. The closely related species of finches had beak of different shapes and sizes, and adapted for feeding on completely different diets. Darwin also found that fossils of Galpagos islands are most similar to living species of South America. The food supply increases in arithmetic ratio but the population increases in geometric ratio.With the study of this theory it struck to Darwin that there is struggle for existence among plants and animals.
Which of the following are necessary for evolution by natural selection to take place?
1. Offspring resemble their parents more than other individuals in the population.
2. Differences among individual sexist and lead to different numbers of successful offspring being produced.
3. Individuals adjust their development depending on the environment.
4. Every individual has a desire to have many offspring.
5. Populations tend to grow faster than their food supplies.
Which one of the following in birds, indicates their reptilian ancestry?
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Solution
Scales on their hind limbs and eggs with calcareous shell,indicates in birds about their reptilian ancestry.
One of the important consequences of geographical isolation is:
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Solution
Speciation takes place via reproductive isolation which is the most important consequence of geographical isolation.
What is common to whale, seal and shark?
The concept of chemical evolution is based on:
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Solution
The concept of chemical evolution is based on possible origin of life by combination of chemicals under suitable environmental conditions. The distribution of elements in the cosmos is the result of many processes in the history of the Universe. It provides us with a powerful tool to study the Big Bang, synthesis and the formation and evolution of stars and galaxies.
Which one of the following statement is correct?
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Solution
Ontogeny repeats phylogeny.
Hand of man, wing of bat and flipper of seal represent:
The four elements that make up 99% of all elements found in a living system are:
Darwin’s finches are a good example of :
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Solution
Darwin finches a good example of adaptive radiation. Adaptive radiation is a process of evolution of different species in a given geographical area starting from a point and radiating to other areas of geography.