Which of the following is dioecious?

Options

A. Pheretima
B. Hirudinaria
C. Nereis
D. Hydra

Answer

To determine which of the following organisms is dioecious, we need to understand the term "dioecious." Dioecious organisms have separate male and female individuals, meaning that the male and female reproductive organs are located on different individuals.

Let's analyze the options provided:

1. **Option A: Ferritima (Earthworm)**
- Earthworms are hermaphrodites, meaning they possess both male and female reproductive organs in the same individual. Therefore, Ferritima is not dioecious.

2. **Option B: Herodineria (Leech)**
- Leeches are also hermaphroditic, having both male and female reproductive organs in one individual. Thus, Herodineria is not dioecious.

3. **Option C: Nereis**
- Nereis is a type of polychaete worm that is dioecious. In Nereis, male and female reproductive organs are located on separate individuals, making it dioecious.

4. **Option D: Hydra**
- Hydra is another organism that is hermaphroditic, containing both male and female reproductive organs in the same individual. Therefore, Hydra is not dioecious.

Based on the analysis of each option, the correct answer is:

**Option C: Nereis** is dioecious.

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