Question

A female Drosophila contains two XX chromosomes while a male Drosophila contains only one X chromosome. However, the amounts of enzymes or even RNA produced by the X-linked genes in the females are equal to those in the males. The reasons are -
(A) The translation machinery in the female is not as efficient as that in the male Drosophila
(B) The X-linked genes in the female Drosophila are highly regulated to make a balance in the expression of genes between males and females
(C) One X-chromosome in the female Drosophila is inactivated
(D) The Y-chromosome in the male Drosophila acts as an X-chromosome to make a balance in product development.
Choose the correct answer from the options given below :

• A. (A), and (B) only.
• B. (B) and (C) only.
• C. (C) and (D) only.
• D. (A) and (D) only.

Hint:

Remember the species-specific mechanisms of dosage compensation:
- Mammals: One X chromosome is inactivated in females (Barr body).
- Drosophila: The single X chromosome in males is hypertranscribed twofold.
- C. elegans: Both X chromosomes in hermaphrodites are transcribed at half-rate.

Answer 1

The Correct Option is A