Question

The cell membrane of a muscle fiber is called a ________.

1. myofibril
2. sarcolemma
3. sarcoplasm
4. myofilament

Short answer

The correct answer is option (b)

Sarcolemma is the name of a muscle fiber's cell membrane.

Step-by-step solution

 Sarcolemma 

• The sarcolemma, which is the muscle cell's plasma membrane, is encircled by endomysia connective tissue and basement membrane.
• The sarcolemma is a membrane that is reactive and has several characteristics in common with the membrane of neuronal cells.

Step: 1 Explanation for Correct answer  

• Sarcolemma and sarcoplasm are the names of the cytoplasm and membrane, respectively, of muscle cells.
• Due to their lengthy, cylindrical structure, muscle cells are also referred to as muscle fibres. A glycocalyx covers the sarcolemma. Thus, the option b is correct.

Step: 2 Explanation for incorrect answer 

• A myofibril is a fundamental rod-shaped organelle of a muscle cell, sometimes referred to as a muscle filament or sarcostyle. So, option a is wrong.
• A muscle fiber's cytoplasm is called sarcoplasm. So, option c is wrong as well.
• The three protein filaments that make up myofilaments are found in muscle cell myofibrils. Myosin, actin, and titin are the three major proteins involved. Hence, option d is wrong too.