The total no.of segmental ganglia in cockroach are 

Options

A. 7
B. 9
C. 8
D. 12

Answer

To determine the total number of segmental ganglia in a cockroach, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Body Structure of Cockroach**:
- The cockroach's body is divided into three main parts: the head, thorax, and abdomen. However, for the purpose of counting segmental ganglia, we focus on the thorax and abdomen.

2. **Identify the Ganglia in the Thorax**:
- The thorax of a cockroach has three segments: prothorax, mesothorax, and metathorax. Each of these segments contains one ganglion.
- Therefore, the total number of ganglia in the thorax = 3.

3. **Identify the Ganglia in the Abdomen**:
- The abdomen of a cockroach consists of 10 segments. However, not all segments contain ganglia.
- The ganglia are present in segments 1, 2, 3, 4, 6, and 7 of the abdomen. This gives us a total of 6 ganglia from the abdominal segments.

4. **Calculate the Total Number of Segmental Ganglia**:
- Now, we add the number of ganglia from the thorax and abdomen together:
- Total ganglia = Thoracic ganglia + Abdominal ganglia
- Total ganglia = 3 (thorax) + 6 (abdomen) = 9.

5. **Conclusion**:
- Therefore, the total number of segmental ganglia in a cockroach is **9**.