In a copulating pair of earthworm, which two processes take place ?

Options

A. External fertilization and cross fertilization
B. Cross fertilization and reciprocal fertilization
C. Internal fertilization and cross fertilization
D. Reciprocal fertilization and internal fertilization

Answer

### Step-by-Step Solution:

1. **Understanding Earthworm Anatomy**:
- Earthworms are hermaphrodites, meaning they possess both male and female reproductive organs in the same individual. This allows them to engage in reproduction without the need for separate male and female earthworms.

2. **Identifying the Processes**:
- In a copulating pair of earthworms, two main processes occur:
- **Cross Fertilization**: This is the process where the sperm from one earthworm fertilizes the eggs of another earthworm.
- **Internal Fertilization**: This occurs when the fertilization of the egg by the sperm happens inside the body of the earthworm.

3. **Mechanism of Cross Fertilization**:
- During copulation, the earthworms align themselves ventrally and exchange sperm. Each earthworm releases sperm that is stored in the other’s body, leading to fertilization of eggs.

4. **Conclusion**:
- Therefore, the two processes that take place in a copulating pair of earthworms are **cross fertilization** and **internal fertilization**.