In Earthworm, both sexes are present and they undergo :

Options

A. Cross fertilization
B. Asexual reproduction
C. Self fertilization
D. Both (1) and (3)

Answer

**Step-by-Step Solution:**

1. **Understanding the Earthworm's Reproductive System**:
- Earthworms are known to be hermaphrodites, meaning they possess both male and female reproductive organs within the same individual. This characteristic is referred to as being monoecious.

2. **Identifying the Type of Fertilization**:
- In earthworms, the type of fertilization that occurs is cross fertilization. This means that during reproduction, two earthworms exchange sperm with each other rather than fertilizing their own eggs.

3. **Mating Process**:
- During mating, two earthworms align themselves ventrally (belly to belly) with their heads pointing in opposite directions. This positioning allows for the mutual exchange of sperm between the two individuals.

4. **Understanding Protandry**:
- The phenomenon of protandry is significant in earthworms. In this process, the male reproductive organs (testes) mature before the female reproductive organs (ovaries). This ensures that when earthworms mate, they can exchange sperm effectively.

5. **Eliminating Incorrect Options**:
- Asexual reproduction is not applicable to earthworms as they reproduce sexually.
- Self-fertilization is also incorrect because it requires both reproductive organs to mature simultaneously, which does not happen in earthworms due to protandry.

6. **Conclusion**:
- Therefore, the correct answer to the question is that in earthworms, both sexes are present and they undergo cross fertilization.

**Final Answer**: In Earthworm, both sexes are present and they undergo cross fertilization.

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