Which of the following act as a brain in cockroach ?

Options

A. Suprapharyngeal ganglion
B. Supraoesophageal ganglion
C. Ventral never cord
D. Segmental ganglion

Answer

To determine which structure acts as the brain in a cockroach, we need to analyze the options provided and understand the anatomy of the cockroach.

### Step-by-Step Solution:

1. **Identify the Options**: The question presents four options related to the nervous system of the cockroach. These options are:
- Suprapharyngeal ganglion
- Supraesophageal ganglion
- Ventral cord
- Segmental ganglion

2. **Understand the Function of Each Option**:
- **Suprapharyngeal ganglion**: This is primarily associated with earthworms (e.g., Lumbricus) and is not the brain of the cockroach.
- **Supraesophageal ganglion**: This structure is known to form the brain in arthropods, including insects like the cockroach.
- **Ventral cord**: This is a nerve cord that runs along the length of the body and is not considered the brain.
- **Segmental ganglion**: This is found in annelids and arthropods and is involved in the segmentation of the body but does not function as a brain.

3. **Identify the Correct Answer**: Based on the understanding that the supraesophageal ganglion forms the brain in arthropods, including cockroaches, we can conclude that the correct answer is the **Supraesophageal ganglion**.

4. **Final Conclusion**: The structure that acts as the brain in a cockroach is the **Supraesophageal ganglion**.