Question

In Drosophila the XXY condition leads to femaleness whereas in human beings the same condition leads to Klinefelter's syndrome in male. It proves that

• A. In human beings, Y chromosome is active in sex determination.
• B. Y chromosome is active in sex determination in both human beings and $Drosophila$.
• C. In $Drosophila$, Y chromosome decides femaleness.
• D. Y chromosome of man has genes for syndrome.

Answer 1

The correct option is A In human beings, Y chromosome is active in sex determination.

The ratio of X chromosmes to the number of sets of autosomes determine the sex in Drosophila. Here, presence or absence of "Y-chromosome" does not affect the sex of the organism. In human, presence or absence of "Y-chromosome" determine the sex. That's why, the XXY condition leads to femaleness in Drosophila but in human beings the same condition leads to Klinefelter's syndrome in male. Option A is correct answer.