Which is absent in blood of Cockroach ?

Options

A. Plasma
B. Respiratory pigment
C. Nurtients
D. Blood cells

Answer

To answer the question "Which is absent in the blood of Cockroach?", we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Circulatory System of Cockroach**:
- The circulatory system of a cockroach is classified as an open circulatory system. This means that the blood (hemolymph) is not confined to blood vessels but instead flows freely in the body cavity.

2. **Identify the Components of Cockroach Blood**:
- Cockroach blood is known as hemolymph. It is a fluid that fills the body cavity and bathes the internal organs.

3. **Check for Respiratory Pigments**:
- In many organisms, blood contains respiratory pigments like hemoglobin, which are responsible for transporting oxygen. However, in the case of cockroaches, their blood does not contain hemoglobin.

4. **Conclude the Absence of Specific Components**:
- Since cockroach blood lacks hemoglobin and other respiratory pigments, we can conclude that these components are absent in their blood.

5. **Final Answer**:
- Therefore, the correct answer to the question is that "respiratory pigments" are absent in the blood of cockroaches.