Assertion: | Female must have the colour blindness gene on both of their X chromosomes to be colour blind. |
Reason: | Colour blindness is a sex linked dominant trait. |
1. | Both Assertion and Reason are true but the Reason does not correctly explain the Assertion. |
2. | Both Assertion and Reason are true and the Reason correctly explains the Assertion. |
3. | Assertion is false and Reason is also false. |
4. | Assertion is true but Reason is false. |
I: | F1 resembled either of the two parents in co-dominance |
II: | F1 was in-between in complete dominance. |
III: | F1 generation resembles both parents in incomplete dominance. |
Statement I: | BB homozygotes produce large starch grains, Bb heterozygotes produce large starch grains and bb homozygotes produce smaller starch grains. |
Statement II: | BB homozygotes produce round seeds, Bb heterozygotes produce oval seeds and bb homozygotes produce wrinkled seeds. |
1. | Statement I is correct; Statement II is correct |
2. | Statement I is correct; Statement II is incorrect |
3. | Statement I is incorrect; Statement II is incorrect |
4. | Statement I is incorrect; Statement II is correct |
1. | Communication was not easy in those days. |
2. | His concept of genes (or factors, in Mendel’s words) as stable and discrete units that controlled the expression of traits and, of the pair of alleles which did not ‘blend’ with each other, was not accepted by his contemporaries as an explanation for the apparently continuous variation seen in nature. |
3. | Mendel’s approach of using mathematics to explain biological phenomena was totally new and unacceptable to many of the biologists of his time. |
4. | Although Mendel’s provided correct physical proof for the existence of unit factors as discrete entities, his explanations could mot convince others. |
1. | de Vries, Correns and von Tschermak | Independently rediscovered Mendel’s laws |
2. | Walter Sutton and Theodore Boveri | Gave chromosomal theory of inheritance |
3. | Sturtevant | Discovered the mechanism of sex determination in fruit flies |
4. | T. H. Morgan | Demonstrated that genes are carried on chromosomes |