Heart in amphibians is

Options

A. Two-chambered with one auricle and one ventricle
B. Three-chambered with two auricles and one ventricle
C. Three-chambered with one auricles and two ventricles
D. Four-chambered with two auricles and two ventricles

Answer

### Step-by-Step Solution:

1. **Identify the Structure of the Amphibian Heart**:
- Amphibians possess a heart that is primarily characterized by having three chambers.

2. **Determine the Number of Auricles and Ventricles**:
- The heart consists of two auricles (also known as atria) and one ventricle. This means there are two upper chambers (auricles) and one lower chamber (ventricle).

3. **Understand Blood Mixing**:
- In the amphibian heart, the oxygenated blood from the lungs and the deoxygenated blood from the body mix in the single ventricle. This results in a mixture of oxygen-rich and oxygen-poor blood.

4. **Implications of Blood Mixing**:
- Due to the mixing of blood in the ventricle, the body of the amphibian does not receive fully oxygenated blood. This is a significant characteristic of their circulatory system.

5. **Classify the Circulatory System**:
- The circulatory system of amphibians is classified as an incomplete double circulatory system. This means that while there are two circuits (pulmonary and systemic), the mixing of blood leads to inefficiencies in oxygen delivery.

6. **Final Answer**:
- Therefore, the correct answer to the question "Heart in amphibians is" is that it is **3-chambered with 2 auricles and 1 ventricle**.