Sex is united in

Options

A. Leech
B. Earthworm
C. Nereis
D. Both 1 & 2

Answer

To answer the question "Sex is united in," we need to analyze the options provided and understand the reproductive characteristics of the organisms listed.

### Step-by-Step Solution:

1. **Identify the Organisms**: The options given are:
- A. Leech
- B. Earthworm
- C. Nereis
- D. Both 1 and 2

2. **Understand the Terms**:
- **Monocious (or Hermaphroditic)**: This term refers to organisms that have both male and female reproductive organs in the same individual.
- **Dioecious**: This term refers to organisms where male and female reproductive organs are found in separate individuals.

3. **Analyze Each Option**:
- **Leech**: Leeches are hermaphroditic, meaning they possess both male and female reproductive organs. Therefore, they exhibit a monocious condition.
- **Earthworm**: Earthworms are also hermaphroditic and have both male and female reproductive organs in the same individual, indicating a monocious condition.
- **Nereis**: Nereis, on the other hand, is dioecious, meaning it has separate male and female individuals.

4. **Conclusion**: Since both leeches and earthworms have united sexes (monocious condition), the correct answer to the question is:
- **D. Both 1 and 2 (Leech and Earthworm)**.

### Final Answer:
The answer to the question "Sex is united in" is **D. Both 1 and 2 (Leech and Earthworm)**.

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