All are incorrect for fruitly, except

Options

A. could be grown on simple synthetic medium in laboratory
B. they complete their life cycle in about two days
C. it has many types of herediatary variations that can be seen with high power microscopes
D. there is clear differentiation of the sexes, males are slightly larger in size than females

Answer

### Step-by-Step Solution:

1. **Understand the Question**: The question asks us to identify the correct statement about fruit flies (Drosophila melanogaster) among several options.

2. **Evaluate Each Statement**:
- **Statement A**: "They can be grown in laboratory on simple synthetic medium."
- This statement is **correct**. Fruit flies can be cultivated easily in a laboratory setting using a simple synthetic medium, which is one of the reasons they are widely used in genetic research.

- **Statement B**: "Their life cycle is completed in 2 days."
- This statement is **incorrect**. While fruit flies have a relatively short life cycle, it typically takes about 10-14 days for their life cycle to complete, not just 2 days.

- **Statement C**: "There are many types of hereditary variations which can be seen with high power microscope."
- This statement is **incorrect**. Although fruit flies exhibit various hereditary variations, these can be observed with a low power microscope or even with the naked eye, not necessarily requiring a high power microscope.

- **Statement D**: "There is a clear differentiation of sexes where male is slightly bigger than female."
- This statement is **incorrect**. In fact, female fruit flies are generally larger than males, which is the opposite of what this statement claims.

3. **Conclusion**: Based on the evaluation, the only correct statement is **Statement A**: "They can be grown in laboratory on simple synthetic medium." Thus, this is the answer to the question.