In Drosophilia the XXY condition leads to femaleness whereas in human beings the same conditions leads to Klienfelter's syndrome in male. It proves:

Options

A. Y Chromosome is active in sex determination in both human beings and drosophilia
B. In drosphilia Y-chromosome decides femaleness.
C. Y chromosome of man have genes for syndrome.
D. In human beings Y chromosome is active in sex determination.

Answer

### Step-by-Step Solution:

1. **Understanding the Chromosomal Conditions**:
- In Drosophila (fruit flies), the sex is determined by the ratio of X chromosomes to Y chromosomes. The presence of two X chromosomes (XX) typically results in a female, while the presence of a Y chromosome does not influence the sex determination. Therefore, an XXY condition in Drosophila still leads to femaleness.

2. **Drosophila's Sex Determination**:
- In Drosophila, the Y chromosome does not play a role in determining sex. Thus, the XXY configuration results in a female phenotype because the presence of two X chromosomes is sufficient for femaleness.

3. **Human Chromosomal Conditions**:
- In humans, the presence of a Y chromosome is crucial for male development. The typical male condition is XY, while the typical female condition is XX. An XXY condition in humans leads to Klinefelter syndrome, which is characterized by male individuals who have an extra X chromosome.

4. **Klinefelter Syndrome Characteristics**:
- Males with Klinefelter syndrome (XXY) often exhibit feminine characteristics such as breast development and a higher-pitched voice. This condition arises due to the presence of an additional X chromosome that influences the development of these traits.

5. **Conclusion**:
- The comparison between Drosophila and humans shows that the role of the Y chromosome in sex determination is different in these two organisms. In Drosophila, the Y chromosome is not necessary for determining maleness or femaleness, while in humans, it is essential for male development. Thus, the XXY condition leads to different outcomes in these species, highlighting the complexity of sex determination mechanisms across different organisms.

### Final Statement:
- The XXY condition leads to femaleness in Drosophila and Klinefelter syndrome in humans, proving that the role of the Y chromosome in sex determination is not universal and varies between species.