Which character is not associated with white muscle fibres ?

Options

A. Less quantity of myoglobin.
B. Number of mitochondria a few.
C. Amount of sarcoplasmic reticulum is low.
D. Depend on anaerobic process for energy.

Answer

To determine which character is not associated with white muscle fibers, we need to analyze the characteristics of white muscle fibers in comparison to the options provided.

### Step-by-Step Solution:

1. **Understanding Muscle Fiber Types**:
- There are two main types of muscle fibers: red muscle fibers (slow-twitch) and white muscle fibers (fast-twitch).
- Red muscle fibers are rich in myoglobin and mitochondria, while white muscle fibers have different characteristics.

2. **Analyzing the Options**:
- **Option 1: Less quantity of myoglobin**:
- White muscle fibers have a lower amount of myoglobin compared to red muscle fibers. This is true.
- **Option 2: Number of mitochondria is few**:
- White muscle fibers contain fewer mitochondria than red muscle fibers. This is also true.
- **Option 3: Amount of sarcoplasmic reticulum is low**:
- White muscle fibers actually have a higher amount of sarcoplasmic reticulum compared to red muscle fibers, which is used for storing calcium ions necessary for muscle contraction. This statement is false.
- **Option 4: Depend upon anaerobic process of energy**:
- White muscle fibers primarily rely on anaerobic respiration for energy due to their lower oxygen availability. This is true.

3. **Identifying the Incorrect Statement**:
- From the analysis, we see that the only statement that does not correctly describe white muscle fibers is **Option 3**, which states that the amount of sarcoplasmic reticulum is low. This is not associated with white muscle fibers.

### Conclusion:
The character that is not associated with white muscle fibers is **Option 3: Amount of sarcoplasmic reticulum is low**.

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