Myofibrils show dark and light bands is

Options

A. Cardiac muscles
B. Unstriped muscles
C. Striped muscles
D. Both A and C.

Answer

### Step-by-Step Solution:

1. **Identify the Types of Muscles**: The question asks about myofibrils showing dark and light bands in different types of muscles. The three types of muscles to consider are:
- Cardiac Muscle
- Smooth Muscle (Unstriated Muscle)
- Skeletal Muscle (Striated Muscle)

2. **Understand Myofibril Structure**: Myofibrils are the contractile elements in muscle fibers. They are composed of repeating units called sarcomeres, which contain thick (myosin) and thin (actin) filaments.

3. **Recognize the Presence of Striations**:
- **Skeletal Muscle**: This type of muscle is striated, meaning it has alternating dark (A bands) and light (I bands) regions due to the arrangement of myosin and actin filaments.
- **Cardiac Muscle**: Cardiac muscle is also striated and contains dark and light bands similar to skeletal muscle, due to the presence of myofibrils.
- **Smooth Muscle**: This type of muscle is unstriated and does not show distinct dark and light bands.

4. **Conclusion**: Based on the above understanding, both cardiac muscle and skeletal muscle show dark and light bands due to the presence of myofibrils. Smooth muscle does not show these bands.

5. **Final Answer**: Therefore, the correct answer to the question is that myofibrils show dark and light bands in both cardiac muscles (A) and skeletal muscles (C).