Heart is four chambered in

Options

A. Amphibia
B. Fishes
C. Mammals
D. Reptiles

Answer

To solve the question "Heart is four chambered in", we need to analyze the options provided: amphibians, fishes, mammals, and reptiles. Here’s a step-by-step breakdown:

### Step 1: Understand the Heart Structure in Different Groups
- **Amphibians**: Amphibians, such as frogs, typically have a three-chambered heart. This consists of two atria and one ventricle.
- **Fishes**: Fishes have a two-chambered heart, which includes one atrium and one ventricle.
- **Reptiles**: Most reptiles have a three-chambered heart as well, with the exception of crocodiles, which have a four-chambered heart.
- **Mammals**: Mammals have a four-chambered heart, which consists of two atria and two ventricles.

### Step 2: Identify the Correct Answer
From the analysis:
- Amphibians: three chambers
- Fishes: two chambers
- Reptiles: three chambers (except crocodiles)
- Mammals: four chambers

Thus, the only group among the options that consistently has a four-chambered heart is **mammals**.

### Step 3: Conclusion
The correct answer to the question "Heart is four chambered in" is **mammals**.

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