Select the correct option

Options

A. HMM=Tail+ short arm
B. LMM=Tail + Head
C. HMM=Head+short arm
D. LMM=Head

Answer

To solve the question regarding the correct options related to heavy meromycin (HMM) and light meromycin (LMM), we can break down the information provided in the video transcript step by step.

### Step-by-Step Solution:

1. **Understanding the Components**:
- We know that muscle fibers consist of two main types of proteins: actin (thin filament) and myosin (thick filament).
- Myosin can be further divided into heavy meromycin (HMM) and light meromycin (LMM).

2. **Identifying HMM**:
- Heavy meromycin (HMM) is characterized as consisting of the head region and the short arm.
- Therefore, we can conclude that HMM = head + short arm.

3. **Identifying LMM**:
- Light meromycin (LMM) is primarily associated with the tail region of the myosin protein.
- Thus, LMM = tail.

4. **Evaluating the Options**:
- **Option 1**: HMM = tail + short arm. This is incorrect because HMM consists of the head, not the tail.
- **Option 2**: LMM = tail + head. This is incorrect because LMM consists only of the tail.
- **Option 3**: HMM = head + short arm. This is correct as per our earlier conclusion.
- **Option 4**: LMM = head. This is incorrect because LMM does not include the head.

5. **Conclusion**:
- The correct option is **Option 3**, which states that heavy meromycin (HMM) is equal to head plus short arm.

### Final Answer:
The correct option is **Option 3: HMM = head + short arm**.

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