Which of the following is correct about the reproductive system of a male cockroach?

Options

A. Ejaculatory duct is between seminal vesicles and phallic gland
B. Duct of phallic gland opens in the left phallomere
C. Mushroom glands open in ejaculatory duct
D. Spermatophore is 2 layered in seminal vesicles.

Answer

To solve the question regarding the reproductive system of a male cockroach, we will analyze each option provided and determine which statement is correct.

### Step-by-Step Solution:

1. **Understanding the Structure of Male Cockroach Reproductive System**:
- The male cockroach has a complex reproductive system that includes various glands and ducts.

2. **Analyzing the First Statement**:
- **Statement**: "Ejaculatory duct is between seminal vesicle and phallic gland."
- **Analysis**: The ejaculatory duct is not located between the seminal vesicle and the phallic gland. It is actually situated on the dorsal side of the body and opens into the gonopore (male genital opening).
- **Conclusion**: This statement is **incorrect**.

3. **Analyzing the Second Statement**:
- **Statement**: "Duct of phallic gland opens into left phallomere."
- **Analysis**: The phallic gland is a small gland in male cockroaches, and its duct indeed opens into the left phallomere, which is a part of the male genitalia.
- **Conclusion**: This statement is **correct**.

4. **Analyzing the Third Statement**:
- **Statement**: "Mushroom gland opens into ejaculatory duct."
- **Analysis**: The mushroom gland is an individual gland located near the ejaculatory duct, but it does not open into it. Therefore, this statement is **incorrect**.

5. **Analyzing the Fourth Statement**:
- **Statement**: "Spermatophore is two-layered in seminal vesicle."
- **Analysis**: While the spermatophore can be described as having two layers (primary and secondary), it does not remain in the seminal vesicle. Instead, it is formed in the sperm mass. Thus, this statement is also **incorrect**.

### Final Conclusion:
The only correct statement about the reproductive system of a male cockroach is that the **duct of the phallic gland opens into the left phallomere**. Therefore, the correct answer is **option no. 2**.

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