Read the following statements and mark the incorrect statement regarding cardiac muscle.

Options

A. It is a contractile tissue present in heart
B. They are not under the control of will of the animals
C. They show relatively rapid contraction
D. Muscle fibers are multinucleated

Answer

To determine the incorrect statement regarding cardiac muscle, let's analyze each statement provided in the question step by step.

### Step-by-Step Solution:

1. **Statement Analysis**:
- **Statement 1**: "It is a contractile tissue present in heart."
- This statement is correct. Cardiac muscle is indeed a contractile tissue that is found only in the heart.

2. **Statement 2**: "They are not under the control of will of the animals."
- This statement is also correct. Cardiac muscles are involuntary muscles, meaning they function without conscious control.

3. **Statement 3**: "They show relatively rapid contraction."
- This statement is incorrect. Cardiac muscles contract relatively slowly compared to skeletal muscles. They are designed for endurance and continuous function rather than rapid contraction.

4. **Statement 4**: "Muscle fibers are multinucleated."
- This statement is incorrect. Cardiac muscle fibers typically have a single nucleus. They are branched and interconnected through intercalated discs.

### Conclusion:
Based on the analysis, the incorrect statement regarding cardiac muscle is **Statement 3**: "They show relatively rapid contraction."

### Final Answer:
The incorrect statement regarding cardiac muscle is: "They show relatively rapid contraction."

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