Earthworm possesses hearts

Options

A. one pair
B. 12 (six pairs)
C. 8 (four pairs)
D. 6 (three pairs)

Answer

To answer the question about how many hearts an earthworm possesses, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Earthworm Anatomy**:
- Earthworms are classified as terrestrial invertebrates. They do not have a true heart like vertebrates but possess structures that perform a similar function.

2. **Circulatory System of Earthworms**:
- Earthworms have a closed circulatory system, which is different from the open circulatory systems found in many other invertebrates.

3. **Identification of Heart-like Structures**:
- Instead of a true heart, earthworms have aortic arches. These arches connect the dorsal and ventral blood vessels, helping in the circulation of blood.

4. **Counting the Aortic Arches**:
- Earthworms have a total of 4 pairs of aortic arches. These are located in specific segments of the earthworm's body.

5. **Location of Aortic Arches**:
- The aortic arches are found in segments 7, 8, 9, 10, 11, 12, and 13. Specifically, there are:
- 1 pair in the 7th segment
- 1 pair in the 8th segment
- 1 pair in the 9th segment
- 1 pair in the 12th segment
- 1 pair in the 13th segment

6. **Conclusion**:
- Since there are 4 pairs of aortic arches in total, the correct answer to the question is that earthworms possess **4 pairs of hearts**.

### Final Answer:
- The correct option is **4 pairs** (Option 3).