In female Drosphila the linked gene exhibit recombination during meiosis of gamete formation, but such a recombination does not occur during the formation of sperm in male Drosophila

Options

A. Male Drosophila is sterile
B. Male Drosophila is parthenogenetic male
C. No crossing over occur in male Drosophila
D. Male Drosophila is haploid

Answer

To solve the question regarding the recombination of linked genes in female and male Drosophila, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Recombination**: Recombination is the process by which genetic material is mixed during meiosis, resulting in offspring with combinations of traits that differ from those of the parents. This typically occurs during the formation of gametes.

2. **Meiosis in Female Drosophila**: In female Drosophila, linked genes can undergo recombination during meiosis. This means that during the formation of eggs, the genes can exchange segments, leading to genetic variation.

3. **Meiosis in Male Drosophila**: In contrast, during the formation of sperm in male Drosophila, recombination does not occur. This is due to the presence of complete linkage between the genes, which means that the genes are inherited together without being separated by crossing over.

4. **Understanding Complete Linkage**: Complete linkage refers to the situation where two or more genes are located very close to each other on the same chromosome and tend to be inherited together. This results in no crossing over occurring during meiosis in males.

5. **Analyzing the Options**:
- **Male Drosophila is sterile**: This is incorrect as male Drosophila can produce sperm.
- **Male Drosophila is parthenogenetic**: This is also incorrect as parthenogenesis refers to a form of asexual reproduction.
- **No crossing over occurs in male Drosophila**: This is correct, as explained above.
- **Male Drosophila is diploid**: While male Drosophila are diploid, this does not directly relate to the question about recombination.

6. **Conclusion**: The correct answer is that no crossing over occurs in male Drosophila due to complete linkage of the genes.

### Final Answer:
**No crossing over occurs in male Drosophila.**

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