Question

Select the incorrect statement regarding sex chromosome:

• A. Human males have one of their sex chromosomes much shorter than the other
• B. The male fruit fly is heterogametic
• C. In male grasshoppers, 50% of sperms have no sex-chromosome
• D. In domesticated fowls, the sex of progeny depends on the type of sperm rather than the egg

Answer 1

The correct option is D

In domesticated fowls, the sex of progeny depends on the type of sperm rather than the egg

The correct option is option D.

Explanation for correct option:

1. The domesticated female fowls are heterogametic.
2. They have ZW type of sex chromosomes.
3. On the other hand, the male fowls are homogametic having ZZ-type of chromosomes.
4. Thus the sex of the progeny organisms depends on the type of egg rather than the sperm.

Explanation for incorrect options:

Option A:

1. Human males are heterogametic and have XY-type of chromosomes.
2. The Y chromosome in human males is shorter than the X chromosome.

Option B:

1. The male fruit fly has an XY type of chromosome.
2. Hence they are heterogametic.

Option C:

1. Grasshoppers have the XO-XX type of chromosome.
2. The male has an XO type of chromosome while the female has an XX type of chromosome.
3. Therefore in males, half of the chromosomes have an X chromosome and the other half have no sex chromosome.

Final answer: The incorrect statement regarding sex chromosomes is that in domesticated fowls, the sex of progeny depends on the type of sperm rather than the egg.