Drosophila is used in the study of genetics because

Options

A. it is hermaphrodite
B. generation period is 90-120 simple
C. chromosome complement is simple with three pairs of autosomes and XY sex chromosomes where Y chromosome is hooked
D. all of the above

Answer

### Step-by-Step Solution:

1. **Understanding Drosophila**: Drosophila melanogaster, commonly known as the fruit fly, is a model organism extensively used in genetic studies.

2. **Reasons for Using Drosophila in Genetics**:
- **Simple Synthetic Medium**: Drosophila can grow in simple synthetic media, making it easy to culture in a laboratory setting.
- **Short Life Cycle**: The life cycle of Drosophila is very short, approximately two weeks, allowing for quick generation of results.
- **High Progeny Production**: During a single mating, Drosophila can produce a large number of offspring, which is advantageous for genetic experiments.
- **Sexual Dimorphism**: Drosophila exhibits clear sexual dimorphism, meaning males and females can be easily distinguished, which is important for genetic studies.
- **Chromosome Complement**: Drosophila has a simple chromosome structure with three pairs of autosomes and one pair of sex chromosomes (XY), which is similar to human chromosomes in terms of genetic similarity (about 75% of genes).

3. **Evaluating the Options**:
- **Option 1**: Incorrect. Drosophila is not hermaphrodite; it has separate male and female individuals.
- **Option 2**: Incorrect. The generation period is not 90 to 120 days; it is about two weeks.
- **Option 3**: Correct. Drosophila has a simple chromosome complement with three pairs of autosomes and XY chromosomes.
- **Option 4**: Incorrect. Since only the third option is correct, "all of the above" cannot be true.

4. **Conclusion**: The correct answer is that Drosophila is used in the study of genetics because of its simple chromosome complement.

### Final Answer:
Drosophila is used in the study of genetics because it has a simple chromosome complement with three pairs of autosomes and XY chromosomes.

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