Gynandromorphs appear in Drosophila because of

Options

A. loss of X-chromosome
B. autosomal loss
C. mutation
D. gain of Y-chromosome

Answer

**Step-by-Step Solution:**

1. **Understanding Gynandromorphs**: Gynandromorphs are organisms that exhibit both male and female characteristics. In Drosophila (fruit flies), these organisms can be seen as genetic mosaics, meaning they contain cells with different genotypes.

2. **Genetic Composition**: In Drosophila, sex determination is primarily based on the number of X chromosomes. Females typically have two X chromosomes (XX), while males have one X and one Y chromosome (XY).

3. **Formation of Gynandromorphs**: Gynandromorphs can arise when there is a loss of one X chromosome during embryonic development. This results in a mixture of cells: some with two X chromosomes (female) and some with only one X chromosome (male).

4. **Genotype Explanation**: If one X chromosome is lost, the resulting genotype can be represented as XXXO (where O indicates the absence of a second sex chromosome). The XX cells represent female characteristics, while the XO cells represent male characteristics.

5. **Conclusion**: Therefore, the appearance of gynandromorphs in Drosophila is primarily due to the loss of an X chromosome during development. Thus, the correct answer to the question is the first option: loss of X-chromosome.

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