In Drosophila male differentiation is controlled by :-

Options

A. (a) No. of Y-chromosome
B. (b) No. of X-chromosomes
C. (c) Ratio between number of X-chromosome and the set of autosome
D. (d) Set of autosomes

Answer

**Step-by-Step Solution:**

1. **Understanding the Question:**
- The question asks about the mechanism that controls male differentiation in Drosophila, a type of fruit fly.

2. **Identifying the Mechanism:**
- In Drosophila, sex determination is based on the ratio of X chromosomes to autosomes. This is known as the genic balance theory.

3. **Explaining the Genic Balance Theory:**
- The genic balance theory, proposed by C.B. Bridges in 1922, states that the sex of Drosophila is determined by the ratio of the number of X chromosomes (X) to the number of sets of autosomes (A).

4. **Determining the Ratios:**
- The following ratios indicate different sexes:
- **X/A = 1:** Normal female Drosophila
- **X/A = 0.5:** Normal male Drosophila
- **X/A between 0.5 and 1:** Intersex individuals
- **X/A > 1:** Super females

5. **Conclusion:**
- Therefore, the correct answer to the question is that male differentiation in Drosophila is controlled by the ratio of the number of X chromosomes to the set of autosomes.

**Final Answer:**
- Male differentiation in Drosophila is controlled by the ratio of the number of X chromosomes to the set of autosomes.

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