In a sarcomere, the thin filaments are bisected by :

Options

A. Z-line
B. M-line
C. H-zone
D. F-line

Answer

To solve the question, "In a sarcomere, the thin filaments are bisected by:", we can follow these steps:

### Step 1: Understand the Structure of a Sarcomere
A sarcomere is the basic structural and functional unit of muscle tissue. It is composed of two types of filaments: thick filaments (myosin) and thin filaments (actin).

**Hint:** Recall that the sarcomere is the repeating unit in striated muscle fibers.

### Step 2: Identify the Filaments
In a sarcomere, the thin filaments are primarily made up of actin, while the thick filaments are made up of myosin. The arrangement of these filaments is crucial for muscle contraction.

**Hint:** Remember that thick and thin filaments work together during muscle contraction.

### Step 3: Locate the Z Line
The Z line (or Z disc) is a key structural feature in the sarcomere. It serves as the boundary between adjacent sarcomeres and is where the thin filaments are anchored.

**Hint:** Think of the Z line as the point where the thin filaments are connected and where they meet from adjacent sarcomeres.

### Step 4: Determine Where the Thin Filaments are Bisected
The question specifically asks where the thin filaments are bisected. The Z line bisects the thin filaments, meaning that the thin filaments extend from the Z line towards the center of the sarcomere.

**Hint:** Visualize the sarcomere structure and see how the filaments are arranged around the Z line.

### Step 5: Conclusion
Based on the understanding of the sarcomere structure, the correct answer to the question is that the thin filaments are bisected by the Z line.

**Final Answer:** The thin filaments in a sarcomere are bisected by the Z line.