| 1. | Haemophilia | 2. | Thalassemia |
| 3. | Sickle-cell anaemia | 4. | Phenylketonuria |
| List-I | List-II | ||
| A. | Incomplete dominance | I. | Human skin colour |
| B. | Co-dominance | II. | Inheritance of flower colour in Antirrhinum sp. |
| C. | Pleiotropy | III. | Phenylketonuria disease in humans |
| D. | Polygenic inheritance | Iv. | ABO blood groups |
| A. | An offspring formed from the union of a sperm and an egg, develops as a female (queen or worker). |
| B. | An unfertilized egg develops as a male by parthenogenesis. |
| C. | A male has half the number of chromosomes than that of a female. |
| D. | Males produce sperm by meiosis. |
| E. | Honeybees have a haplodiploid sex-determination system. |
| 1. | B, C, D and E only | 2. | A, B, C and D only |
| 3. | A, B, D and E only | 4. | A, B, C and E only |
| 1. | 50% |
| 2. | 0% |
| 3. | 75% |
| 4. | 25% |
| 1. | Male honeybees | 2. | Male grasshoppers |
| 3. | Male earthworms | 4. | Male frogs |
| Assertion (A): | In an experiment, Mendel observed that the F1 progeny plants are all tall and none are dwarf. |
| Reason (R): | Stem height is a contrasting trait, with tall being dominant and dwarf being recessive. |
| 1. | (A) is not correct but (R) is correct |
| 2. | Both (A) and (R) are correct and (R) is the correct explanation of (A) |
| 3. | Both (A) and (R) are correct but (R) is not the correct explanation of (A) |
| 4. | (A) is correct but (R) is not correct |
| Statement I: | Down's syndrome is caused by the absence of one of the X-chromosomes. |
| Statement II: | Turner's syndrome is caused by the presence of an additional copy of the chromosomes. |
| 1. | Statement I is incorrect but Statement II is correct |
| 2. | Both Statement I and Statement II are correct |
| 3. | Both Statement I and Statement II are incorrect |
| 4. | Statement I is correct but Statement II is incorrect |