In Drosophila sex index of super female is :-

Options

A. 1
B. `0.5`
C. `1.5`
D. 0.67

Answer

To solve the question regarding the sex index of super female in Drosophila, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Sex Determination in Drosophila**:
- In Drosophila (fruit flies), sex determination is based on the genic balance theory. This theory states that the sex of an organism is determined by the ratio of X chromosomes to the number of sets of autosomes.

2. **Identify the Relevant Ratio**:
- The ratio is calculated as \( \frac{X}{A} \), where:
- \( X \) = number of X chromosomes
- \( A \) = number of sets of autosomes (non-sex chromosomes)

3. **Determine the Condition for Super Female**:
- According to the genic balance theory, if the ratio \( \frac{X}{A} \) is greater than 1, the organism is classified as a super female.

4. **Calculate the Sex Index for Super Female**:
- For a super female, the sex index is defined as 1.5. This means that the presence of additional X chromosomes (more than the number of autosomal sets) leads to a higher sex index.

5. **Select the Correct Option**:
- Given the options (1, 0.5, 1.5, and 0.67), the correct answer for the sex index of a super female in Drosophila is **1.5**.

### Final Answer:
The sex index of super female in Drosophila is **1.5**.

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