Respiratory pigment Fe containing but red in colour `:-`

Options

A. Haemocyanin (Molluscas)
B. Haemoglobin (most vertebrates)
C. Chlorocruorin (Some annelids)
D. None

Answer

To solve the question regarding a respiratory pigment that contains iron and is red in color, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: We need to identify a respiratory pigment that contains iron and is red in color.

2. **Evaluate the Options**:
- The first option is **hemocyanin**.
- **Analysis**: Hemocyanin is a respiratory pigment found in mollusks and some arthropods. It contains copper, not iron, and is colorless. Therefore, it does not meet the criteria of being red in color.
- The second option is **hemoglobin**.
- **Analysis**: Hemoglobin is the respiratory pigment found in most vertebrates. It contains iron at its core and is known for its red color. Hemoglobin can appear dark red when deoxygenated and bright red when oxygenated. Thus, it satisfies both conditions of containing iron and being red in color.

3. **Conclusion**: Based on the evaluations, hemoglobin is the only respiratory pigment that contains iron and is red in color. Therefore, the correct answer is **hemoglobin**.

### Final Answer:
**Hemoglobin** is the respiratory pigment that contains iron and is red in color.

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