Two chambered heart occurs in

Options

A. crocodiles
B. fish
C. aves
D. amphibians

Explanation

**Step-by-Step Text Solution:**

1. **Understanding the Question**: The question asks which organism has a two-chambered heart. The options provided are crocodile, fish, apes, and amphibians.

2. **Analyzing Each Option**:
- **Crocodile**: Crocodiles belong to the phylum Reptilia. Most reptiles have a three-chambered heart, but crocodiles are an exception as they possess a four-chambered heart.
- **Fish**: Fish belong to the phylum Pisces. They have a two-chambered heart, which means they do not separate oxygenated and deoxygenated blood.
- **Apes**: Apes are mammals and have a four-chambered heart, which is typical for mammals to ensure efficient separation of oxygenated and deoxygenated blood.
- **Amphibians**: Amphibians, like frogs, typically have a three-chambered heart, which is similar to reptiles.

3. **Identifying the Correct Answer**: Based on the analysis, the only organism among the options that has a two-chambered heart is the fish.

4. **Conclusion**: Therefore, the correct answer is **fish**.

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