In which , the heart passes through alimentary canal ?

Options

A. Pila
B. Aplysia
C. Unio
D. patella

Answer

To solve the question "In which organism does the heart pass through the alimentary canal?", we will analyze the options given and focus on the characteristics of organisms in the phylum Mollusca.

### Step-by-Step Solution:

1. **Understanding the Phylum Mollusca**:
- Mollusca is a diverse group of invertebrates that primarily live in aquatic environments. They exhibit a variety of body structures and systems.

2. **Circulatory System in Mollusca**:
- Most mollusks have an open circulatory system, where blood is not always contained within blood vessels. However, some classes within Mollusca have a closed circulatory system.

3. **Identifying the Organisms**:
- The question specifically asks for the organism whose heart passes through the alimentary canal. We will examine the options provided:
- **Pila**: This class has a closed circulatory system.
- **Aplasia**: This class has an open circulatory system.
- **Unio**: This class also has an open circulatory system, and it is noted that its heart is associated with the alimentary canal.
- **Patella**: This class is considered primitive and does not have a well-defined alimentary canal.

4. **Conclusion**:
- Among the options, **Unio** is the correct answer as it is known for having its heart associated with the alimentary canal.

### Final Answer:
The organism in which the heart passes through the alimentary canal is **Unio**.

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