Which statement is not true with regard to the circulatory system of coockroach ?

Options

A. Blood of cockroach is colourless
B. There is no respiratory pigment in hemolymph
C. Blood does not function as an oxygen carrier
D. Heart of cockroach is myogenic

Answer

To determine which statement is not true regarding the circulatory system of cockroaches, we will analyze each statement provided.

### Step-by-Step Solution:

1. **Evaluate the First Statement**: "The blood of cockroach is colorless."
- **Analysis**: Cockroach blood, known as hemolymph, is indeed colorless due to the absence of respiratory pigments. This statement is true.

2. **Evaluate the Second Statement**: "There is no respiratory pigment in hemolymph."
- **Analysis**: Hemolymph in cockroaches does not contain respiratory pigments like hemoglobin, which is found in many other organisms. This statement is also true.

3. **Evaluate the Third Statement**: "Blood does not function as an oxygen carrier."
- **Analysis**: Since there are no respiratory pigments in the hemolymph, it cannot effectively carry oxygen. Thus, this statement is true as well.

4. **Evaluate the Fourth Statement**: "The heart of cockroach is myogenic."
- **Analysis**: The heart of a cockroach is actually neurogenic, meaning that its rhythmic contractions are initiated by nerve impulses rather than by the muscle tissue itself. Therefore, this statement is false.

### Conclusion:
The statement that is not true regarding the circulatory system of cockroaches is: "The heart of cockroach is myogenic."

### Final Answer:
The false statement is: "The heart of cockroach is myogenic."

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