Krause membrane or Z- line is a myofibril which separates two adjacent

Options

A. A band or anisotropic band
B. Henson's line
C. I band or isotropic band
D. Sarcomere

Answer

### Step-by-Step Solution:

1. **Understanding Myofibrils**: Myofibrils are the basic rod-like units of a muscle cell (muscle fiber) and are essential for muscle contraction. They are composed of repeating units called sarcomeres.

2. **Identifying Sarcomeres**: A sarcomere is the functional unit of a muscle fiber. It is defined as the segment between two Z lines (or Z discs). Each sarcomere contains thick (myosin) and thin (actin) filaments.

3. **Role of the Z Line**: The Z line (or Z disc) is a structure that marks the boundary of each sarcomere. It is where the thin filaments (actin) are anchored. The Z line plays a crucial role in muscle contraction by helping to maintain the structural integrity of the muscle fiber.

4. **Separation of Sarcomeres**: The Z line separates two adjacent sarcomeres. Each sarcomere is composed of an A band (which contains thick filaments) and I bands (which contain thin filaments). The Z line is located at the center of the I band.

5. **Conclusion**: Therefore, the Z line or Krause membrane is a myofibril that separates two adjacent sarcomeres in a muscle fiber.

### Final Answer:
Krause membrane or Z-line is a myofibril that separates two adjacent sarcomeres.

---