Ductus ejaculatorius is present in this abdominal segment 

Options

A. `6^(th)`
B. `4^(th)`
C. `7^(th)`
D. `5^(th)`

Answer

To determine the abdominal segment where the ductus ejaculatorius is present in a cockroach, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Anatomy of the Cockroach**: The cockroach's body is divided into three main parts: the head, thorax, and abdomen. The abdomen consists of 10 segments.

2. **Identify the Male Reproductive System**: The ductus ejaculatorius is part of the male reproductive system in cockroaches. It plays a role in the transfer of sperm.

3. **Locate the Testes**: The testes, which are the male reproductive organs, are located in the fourth and sixth abdominal segments. This information helps eliminate options that do not contain the ductus ejaculatorius.

4. **Analyze the Abdominal Segments**:
- The fourth and sixth segments contain the testes, so these options can be ruled out.
- The seventh segment, along with the eighth and ninth segments, forms the brood or genital part of the cockroach.

5. **Conclude the Correct Segment**: Since the ductus ejaculatorius is associated with the male reproductive system and is found in the seventh segment, we can conclude that the correct answer is the seventh abdominal segment.

### Final Answer:
The ductus ejaculatorius is present in the **seventh abdominal segment** of the cockroach.

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