Molluscs have

Options

A. 3-4 pairs of hearts
B. A single tubular heart
C. 2-3 chambered heart
D. Multichambered heart.

Answer

**Step-by-Step Solution:**

1. **Understanding Molluscs**: Molluscs are a diverse group of animals within the phylum Mollusca, which includes species such as octopuses, snails, and clams. They are found in various environments, both marine and freshwater.

2. **Circulatory System**: Molluscs have an open circulatory system. This means that their blood (hemolymph) is not entirely contained within blood vessels. Instead, a portion of it flows freely in the body cavity, bathing the organs directly.

3. **Heart Structure**: The heart of molluscs typically consists of two atria and one ventricle. This configuration is classified as a three-chambered heart. The two atria receive blood, while the ventricle pumps it out.

4. **Oxygenation Process**: The heart pumps oxygenated blood to the gills, which are the respiratory organs in molluscs. The gills extract oxygen from water, and the oxygen-rich blood is then circulated to the rest of the body.

5. **Correct Answer**: Based on the structure of the heart and the type of circulatory system, the correct answer to the question "Molluscs have" is that they possess a 2-3 chambered heart, specifically with two atria and one ventricle.

**Final Answer**: Molluscs have a 2-3 chambered heart.

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