Which among the following is an exception of possossing three-chambered heart?

Options

A. Aligator
B. Testudo
C. Chelone
D. Bungarus

Answer

**Step-by-Step Solution:**

1. **Understand the Question**: The question asks for an exception regarding the possession of a three-chambered heart among reptiles. Most reptiles typically have a three-chambered heart.

2. **Identify the General Characteristics**: Generally, reptiles possess a three-chambered heart, which consists of two atria and one ventricle. However, there are exceptions within this group.

3. **Analyze the Options**: The options provided include various reptiles. We need to identify which one does not conform to the typical three-chambered heart structure.

4. **Know the Exception**: Among reptiles, the alligator (and its close relative, the crocodile) is known to possess a four-chambered heart, which consists of two atria and two ventricles. This is the key exception to the rule.

5. **Evaluate Other Options**:
- **Testudo (land tortoise)**: This has a three-chambered heart.
- **Chilon (sea turtle)**: This also has a three-chambered heart.
- **Krait (a type of snake)**: This too has a three-chambered heart.

6. **Conclusion**: The only reptile among the options that possesses a four-chambered heart is the alligator. Therefore, the correct answer to the question is **alligator**.

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