Which of the following is not a characteristic features of biceps muscle?

Options

A. We are usually able to make it contract merely by thinking about it
B. It has alternative light and dark bands
C. Its muscle fibre taper at both ends
D. Its muscle fibres are bundled together in a parallel fashion

Answer

To determine which of the following is not a characteristic feature of the biceps muscle, we can analyze the options provided based on the known characteristics of skeletal muscles, specifically the biceps.

### Step-by-Step Solution:

1. **Understanding Biceps Muscle Characteristics**:
- The biceps muscle is a type of skeletal muscle found in the upper limb (arm).
- It is classified as a voluntary muscle, meaning it can be consciously controlled.

2. **Identifying Key Features of Skeletal Muscles**:
- Skeletal muscles, including the biceps, are striated, which means they have a striped appearance due to the arrangement of actin and myosin filaments.
- They typically have cylindrical muscle fibers that do not taper at both ends.
- The muscle fibers are bundled together in a parallel fashion.

3. **Analyzing the Options**:
- **Option 1**: "We can control it by thinking about it."
- This is true for biceps as they are voluntary muscles.
- **Option 2**: "It has alternatively light and dark bands."
- This is also true as it describes the striated appearance of skeletal muscles.
- **Option 3**: "Its muscle fibers taper at both ends."
- This statement is false for biceps. Biceps muscle fibers are cylindrical and do not taper at both ends; tapering is characteristic of smooth muscles.
- **Option 4**: "Its muscle fibers are bundled together in a parallel fashion."
- This is true as skeletal muscle fibers are arranged in parallel bundles.

4. **Conclusion**:
- The statement that is not a characteristic feature of the biceps muscle is **"Its muscle fibers taper at both ends."** This is characteristic of smooth muscles, not skeletal muscles like the biceps.

### Final Answer:
The characteristic feature that is NOT true for the biceps muscle is: **"Its muscle fibers taper at both ends."**

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