Practicing Success
Practicing Success
CUET Preparation Today
Colour Blindness : It is a sex-linked disorder due to defect in either red or green cone of eye resulting in failure to discriminate between red and green colour. This defect is due to mutation in certain genes present in the X chromosome. It occurs in about 8 per cent of males and only about 0.4 per cent of females. This is because the genes that lead to red-green colour blindness are on the X chromosomes.( Answer questions 1 to 5) |
| Which among the following is sex linked recessive disease?(Question 2) |
Sickle cell anaemia. Phenylketonuria. Haemophilia. Thalassemia. |
| Haemophilia. |
| Haemophilia is sex linked recessive disease which shows its transmission from unaffected carrier female to some of the male progeny has been widely studied. In this disease, a single protein that is a part of the cascade of proteins involved in the clotting of blood is affected. Due to this, in an affected individual a simple cut will result in non-stop bleeding. The heterozygous female (carrier) for haemophilia may transmit the disease to sons. The possibility of a female becoming a haemophilic is extremely rare because mother of such a female has to be at least carrier and the father should be haemophilic (unviable in the later stage of life). while all others are autosomal recessive diseases. |
