| I: | Haemophilia is a sex-linked recessive disease. |
| II: | Down’s syndrome is due to aneuploidy. |
| III: | Phenylketonuria is an autosomal recessive gene disorder. |
| IV: | Sickle cell anaemia is an X-linked recessive gene disorder |
Which of the following most appropriately describes haemophilia?
| 1. | X-linked recessive gene disorder |
| 2. | Chromosomal disorder |
| 3. | Dominant gene disorder |
| 4. | Recessive gene disorder |