Myosin myofilaments are

Options

A. attached to the Z-disk
B. absent from the H-zone
C. found primarly in the I-band
D. none of the above

Answer

To answer the question about myosin myofilaments, let's analyze the options provided step by step.

### Step-by-Step Solution:

1. **Understanding Myosin Myofilaments**:
- Myosin myofilaments are thick filaments found in skeletal muscle. They play a crucial role in muscle contraction by forming cross-bridges with actin filaments.

2. **Analyzing Option A - Attached to the Z disc**:
- The Z disc is the boundary of the sarcomere, and it is where actin filaments are anchored. Myosin filaments do not attach to the Z disc; instead, they are located in the A band of the sarcomere.
- **Conclusion**: This option is incorrect.

3. **Analyzing Option B - Absent from the edge zone**:
- The edge zone of the sarcomere refers to the area at the ends where actin filaments are present. Myosin filaments are not absent from this area; they are present in the A band, which overlaps with the edge zone.
- **Conclusion**: This option is also incorrect.

4. **Analyzing Option C - Found primarily in the I band**:
- The I band is the region of the sarcomere that contains only actin filaments. Myosin filaments are primarily found in the A band, not the I band.
- **Conclusion**: This option is incorrect.

5. **Analyzing Option D - None of the above**:
- Since all the previous options (A, B, and C) are incorrect, the only valid choice left is option D, which states that none of the above statements are true.
- **Conclusion**: This option is correct.

### Final Answer:
The correct answer is **Option D - None of the above**.