Pinnaglobin occurs in

Options

A. Molluse
B. Arthropoda
C. Annelida
D. Myriapoda

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks where the respiratory pigment "pinaglobin" occurs. We need to identify the correct group of organisms from the given options: A. Mollusc, B. Orthopoda, C. Annelida, D. Myriapoda.

2. **Identifying Pinaglobin**: Pinaglobin is described as a brown-colored respiratory pigment. It is important to note its characteristics and compare them with the respiratory pigments found in other groups.

3. **Comparing with Hemocyanin**: The transcript mentions that pinaglobin is similar to hemocyanin, which is a respiratory pigment found in some invertebrates. Hemocyanin contains copper, while pinaglobin contains manganese instead.

4. **Identifying the Organism Group**: The transcript states that hemocyanin is found in mollusks and arthropods (which includes orthopods). However, it specifically mentions that pinaglobin is only found in mollusks.

5. **Conclusion**: Based on the information provided, we conclude that pinaglobin occurs in mollusks. Therefore, the correct answer is option A: Mollusc.

**Final Answer**: A. Mollusc

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