Mixing of oxygenated and deoxygenated blood occurs in the ventricle of

Options

A. Scoliodon
B. Rabbit
C. Frog
D. None of these

Answer

To solve the question about which organism has mixing of oxygenated and deoxygenated blood occurring in the ventricles, we can analyze the heart structure of different organisms step by step.

### Step-by-Step Solution:

1. **Understanding Heart Structures**:
- Different organisms have different types of hearts. The heart can be categorized based on the number of chambers it has: two-chambered, three-chambered, or four-chambered.

2. **Two-Chambered Heart**:
- Organisms like fish have a two-chambered heart, consisting of one atrium and one ventricle. In these organisms, the heart primarily contains deoxygenated blood, and there is no mixing of oxygenated and deoxygenated blood. Therefore, this option is incorrect.

3. **Four-Chambered Heart**:
- Mammals, such as rabbits, have a four-chambered heart, which includes two atria and two ventricles. This structure allows for complete separation of oxygenated and deoxygenated blood, preventing any mixing. Thus, this option is also incorrect.

4. **Three-Chambered Heart**:
- Frogs have a three-chambered heart, which consists of two atria and one ventricle. In this configuration, deoxygenated blood enters the right atrium, while oxygenated blood enters the left atrium. Since there is only one ventricle, both types of blood mix in the ventricle before being pumped to the body. Therefore, this option is correct.

5. **Conclusion**:
- Based on the analysis, the organism in which mixing of oxygenated and deoxygenated blood occurs in the ventricle is the frog.

### Final Answer:
The mixing of oxygenated and deoxygenated blood occurs in the ventricle of the **frog**.

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