Spermatozoa of earthworm mature in the sacs present in &— segments 

Options

A. `10^(th) & 11^(th)`
B. `12^(th) & 13^(th)`
C. `11^(th) & 12^(th)`
D. `13^(th) & 14^(th)`

Answer

To solve the question regarding the maturation of spermatozoa in earthworms, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of Earthworm**:
- Earthworms exhibit metameric segmentation, meaning their body is divided into segments. Each segment can contain different organs.

2. **Identify the Role of Testes**:
- The testes in earthworms are responsible for producing spermatozoa (the early stage of sperm).

3. **Locate the Testis Sacs**:
- The spermatozoa produced in the testes are transported to the testis sacs for maturation.

4. **Determine the Segments Involved**:
- The testis sacs where the maturation of spermatozoa occurs are specifically located in the 10th and 11th segments of the earthworm.

5. **Evaluate the Options**:
- The options provided are:
- 10th and 11th
- 12th and 13th
- 11th and 12th
- 13th and 14th
- Since we established that the maturation occurs in the 10th and 11th segments, this is the correct answer.

6. **Conclusion**:
- The correct answer to the question is that spermatozoa of earthworms mature in the sacs present in the 10th and 11th segments.

### Final Answer:
- Spermatozoa of earthworm mature in the sacs present in **10th and 11th segments**.

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