Which of the following refers to correct example(s) of organisms that have evolved due to changes in environment brought about by anthropogenic action?
(a) | Darwin's Finches of Galapagos islands |
(b) | Herbicide-resistant weeds |
(c) | Drug-resistant eukaryotes |
(d) | Man-created breeds of domesticated animals like dogs |
1. (a) and (c)
2. (b), (c) and (d)
3. only (d)
4. only (a)
Statement I: | Mutations are random and direction less, while Darwinian variations are small and directional. |
Statement II: | Darwin's finches represent one of the best examples of adaptive radiation. |
1. | Both statement I and statement II are correct |
2. | Both statement I and statement II are incorrect |
3. | Statement I is correct but statement II is incorrect |
4. | Statement I is incorrect but statement II is correct |
Assertion (A): | In terms of determination, evolution is a directed process |
Reason (R): | Nature selects those variants which are able to reproduce better and leave more progeny in the changed environmental conditions |
1. | (A) is true but (R) is false |
2. | (A) is false but (R) is true |
3. | Both (A) and (R) are true but (R) is not the correct explanation of (A) |
4. | Both (A) and (R) are true and (R) is the correct explanation of (A) |
Column-I | Column-II | ||
a. | Lamarck | (i) | Origin of life preceded by chemical evolution |
b. | Darwin | (ii) | Reproductive fitness |
c. | Haldane | (iii) | Inheritance of acquired characters |
d. | Malthus | (iv) | Populations are stable in size except for the seasonal fluctuations |
Column I | Column II | ||
a. | Saltation | (i) | Lamarck |
b. | Inheritance of acquired characters | (ii) | Hugo de Vries |
c. | Branching descent and natural selection | (iii) | Darwin |
(iv) | Thomas Malthus |
Assertion(A): | Natural selection is the outcome of difference in survival and reproduction among individual that have shown variation in one or more traits. |
Reason(R): | Adaptive forms of a given trait to become more common. Less adaptive ones become less common or disappear. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Assertion(A): | Fitness is the end result of ability to adapt and get selected by nature. |
Reason(R): | Some organisms are better adapted to survive in an otherwise hostile environment. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Assertion(A): | Sickle cell anaemia in malaria endemic area is an example of directional selection. |
Reason(R): | Individuals for sickle cell anaemia have defective gene in X chromosomes. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Assertion(A): | Branching descent and natural selection are the two key concepts of Darwinian theory. |
Reason(R): | Hardy-Weinberg's equilibrium is not affected by Darwinian natural selection. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |