Morgan worked with Drosophila melanogaster because.
i) they complete their life cycle in two months.
ii) male and female are easily distinguishable.
iii) a single mating could produce a large number of progeny flies.
iv) it has many types of hereditary variations that can be seen with low power microscopes.

Options

A. i,ii
B. ii, iii , iv
C. i,ii , iii
D. i,ii,iii,iv

Answer

To solve the question regarding why Morgan worked with Drosophila melanogaster, we will analyze each statement provided and determine their validity based on known facts about this model organism.

### Step-by-Step Solution:

1. **Evaluate Statement i**: "They complete their life cycle in two months."
- **Analysis**: The life cycle of Drosophila melanogaster is approximately 10-14 days (about 2 weeks) under optimal conditions, not two months. Therefore, this statement is **incorrect**.

2. **Evaluate Statement ii**: "Male and female are easily distinguishable."
- **Analysis**: Drosophila melanogaster exhibits sexual dimorphism, meaning males and females have distinct physical characteristics that make them easily distinguishable. This statement is **correct**.

3. **Evaluate Statement iii**: "A single mating could produce a large number of progeny flies."
- **Analysis**: One mating of Drosophila can result in a large number of offspring. A female can lay hundreds of eggs, making this statement **correct**.

4. **Evaluate Statement iv**: "It has many types of hereditary variations that can be seen with low power microscopes."
- **Analysis**: Drosophila melanogaster is known for its genetic variations, and many of these variations can indeed be observed with a low power microscope. This statement is **correct**.

### Conclusion:
From the analysis:
- Statement i is incorrect.
- Statements ii, iii, and iv are correct.

Thus, the correct answer to the question is that Morgan worked with Drosophila melanogaster for the reasons stated in statements ii, iii, and iv.

### Final Answer:
The correct option is the one that includes statements ii, iii, and iv as valid reasons for Morgan's choice of Drosophila melanogaster.

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