Amphibian heart consists of -

Options

A. Two auricles and one ventricle
B. One auricle and two ventricles
C. Two auricles and two ventricles
D. One sinus venosus, one auricle and 2 ventricles

Answer

**Step-by-Step Solution:**

1. **Understanding the Structure of the Amphibian Heart**: Amphibians, such as frogs and toads, have a unique heart structure that is adapted to their lifestyle, which includes both aquatic and terrestrial phases.

2. **Identifying the Number of Chambers**: The amphibian heart is characterized by having three chambers. These consist of two atria (also known as auricles) and one ventricle.

3. **Analyzing the Function of Each Chamber**:
- The two auricles receive blood: one auricle receives oxygenated blood from the lungs, while the other receives deoxygenated blood from the body.
- The single ventricle pumps blood out to the body and lungs, but because there is only one ventricle, some mixing of oxygenated and deoxygenated blood occurs.

4. **Evaluating the Options**:
- **Option 1**: Two auricles and one ventricle - This is correct as it matches the structure of the amphibian heart.
- **Option 2**: One auricle and two ventricles - This is incorrect as amphibians do not have this configuration.
- **Option 3**: Two auricles and two ventricles - This describes a four-chambered heart, which is found in birds and mammals, not amphibians.
- **Option 4**: One sinus venosus, one auricle, and two ventricles - This is also incorrect as amphibians do not have two ventricles.

5. **Conclusion**: Based on the analysis, the correct answer is that the amphibian heart consists of two auricles and one ventricle.

**Final Answer**: The amphibian heart consists of two auricles and one ventricle.

---