Question

Which of the following statements is correct?

• A. Female carrier for haemophilia may transmit the disease to sons.
• B. Thalassemia is a qualitative problem.
• C. Change in whole set of chromosomes is called aneuploidy
• D. Sickle cell anaemia is a quantitative problem.

Answer 1

The Correct Option is A

Haemophilia is an X-linked recessive disorder. A female carrier (with one normal X chromosome and one X chromosome carrying the defective gene) has a 50% chance of transmitting the defective X chromosome to her sons. Since sons inherit the Y chromosome from their fathers, they can only inherit the X chromosome from their mother. Therefore, a female carrier can pass on the disease to her sons.

The correct answer is (A) : Female carrier for haemophilia may transmit the disease to sons.

Answer 2

The correct answer is: (A) Female carrier for haemophilia may transmit the disease to sons.

Haemophilia is a genetic disorder that impairs the blood's ability to clot properly. It is an X-linked recessive disease, which means the defective gene causing the disorder is located on the X chromosome. Since males have only one X chromosome (XY), a single defective allele on the X chromosome will result in haemophilia. In contrast, females have two X chromosomes (XX), so a single defective allele typically does not cause the disease in females unless both X chromosomes carry the mutation.

A female who carries the haemophilia gene (heterozygous carrier) may pass on the X chromosome with the defective gene to her children. If she passes this X chromosome with the mutation to a son (who inherits only one X chromosome from his mother), the son will have haemophilia. Therefore, a female carrier of haemophilia has a 50% chance of transmitting the disease-causing allele to her sons.

Thus, the correct statement is that a female carrier for haemophilia may transmit the disease to her sons, as stated in option (A).