Which of the following has myogenic heart?

Options

A. Frog
B. Humans
C. Rabbit
D. All of the above

Answer

To determine which of the following organisms has a myogenic heart, we need to understand the difference between myogenic and neurogenic hearts.

### Step-by-Step Solution:

1. **Define Myogenic and Neurogenic Hearts**:
- A **myogenic heart** is one where the heartbeat is initiated by the cardiac muscle itself, without the need for external nerve signals.
- A **neurogenic heart**, on the other hand, relies on nerve signals from the brain to initiate the heartbeat.

2. **Identify the Organisms**:
- The options given are:
- Frog
- Human
- Rabbit
- All of the above

3. **Analyze Each Option**:
- **Frog**: Frogs are vertebrates and possess a myogenic heart. Their heart beats independently of nerve impulses.
- **Human**: Humans also have a myogenic heart. The heart beats due to the intrinsic properties of cardiac muscle cells.
- **Rabbit**: Rabbits, being vertebrates, also have a myogenic heart. Like humans and frogs, their heart functions independently of external nerve input.

4. **Conclusion**:
- Since all three organisms (frog, human, and rabbit) have myogenic hearts, the correct answer is **"All of the above."**

### Final Answer:
The correct option is **"All of the above."**

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