In a myofibril , the band which contains only actin filament is also known as

Options

A. Isotropic band
B. Anisotropic band
C. Inotropic band
D. Dark band

Answer

To solve the question regarding the band in a myofibril that contains only actin filaments, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of Myofibrils**: Myofibrils are the basic rod-like units of a muscle cell and are composed of repeating units called sarcomeres. Each sarcomere contains thick and thin filaments.

2. **Identify the Filaments**: The thick filaments are primarily made of myosin, while the thin filaments are primarily made of actin.

3. **Recognize the Bands in a Sarcomere**: In a sarcomere, there are different bands:
- **A Band**: This band contains both thick (myosin) and thin (actin) filaments.
- **I Band**: This band contains only thin filaments (actin) and is lighter in appearance.
- **H Zone**: This is the central part of the A band where there are only thick filaments (myosin).

4. **Identify the Band with Only Actin**: Since the question specifically asks for the band that contains only actin filaments, we focus on the I Band.

5. **Conclusion**: The band that contains only actin filaments in a myofibril is known as the **I Band** (also referred to as the isotropic band).

### Final Answer:
The band which contains only actin filament in a myofibril is known as the **I Band**.

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