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 in the question step by step.

### Step 1: Analyze the first statement
**Statement:** They complete their life cycle in two months.

**Evaluation:** This statement is incorrect. Drosophila melanogaster actually completes its life cycle in about 14 to 15 days, not two months. Therefore, this statement does not support why Morgan chose to work with this organism.

**Hint:** Check the typical life cycle duration of Drosophila melanogaster to determine if the statement is accurate.

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### Step 2: Analyze the second statement
**Statement:** Male and female are easily distinguishable.

**Evaluation:** This statement is correct. In Drosophila melanogaster, males and females can be easily distinguished by their genitalia. Males have dark rounded genitalia, while females have lighter and pointed genitalia. This characteristic makes it convenient for genetic studies.

**Hint:** Look for physical characteristics that differentiate male and female Drosophila.

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### Step 3: Analyze the third statement
**Statement:** A single mating could produce a large number of progeny flies.

**Evaluation:** This statement is also correct. Drosophila melanogaster is known for its high reproductive rate; a single mating can result in a large number of offspring, which is advantageous for genetic experiments.

**Hint:** Consider the reproductive capacity of Drosophila and how it benefits genetic research.

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### Step 4: Analyze the fourth statement
**Statement:** It has many types of hereditary variations that can be seen with low power microscopes.

**Evaluation:** This statement is correct as well. Drosophila melanogaster exhibits a wide variety of genetic mutations and variations that can be observed under a low power microscope, making it an excellent model organism for genetic studies.

**Hint:** Think about the visibility of genetic variations in Drosophila and their significance in genetics.

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### Conclusion
Based on the analysis:
- Statement 1 is incorrect.
- Statements 2, 3, and 4 are correct.

Thus, the correct answer is that Morgan worked with Drosophila melanogaster because of statements 2, 3, and 4.

**Final Answer:** Morgan worked with Drosophila melanogaster because:
- Male and female are easily distinguishable (Statement 2).
- A single mating could produce a large number of progeny flies (Statement 3).
- It has many types of hereditary variations that can be seen with low power microscopes (Statement 4).