Q.21 - Biology

Question

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

a. myofibril 

b. sarcolemma 

c. sarcoplasm 

d. myofilament 

Step-by-Step Solution

Answer

The correct answer is (b) sarcolemma  

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

Step 1. Introduction

Muscle tissues can be organized based on structure and level, as one components builds on the component of another. The muscle cell membrane envelops several myofibrils. Muscle cells are then bundled together as muscle fascicles. 

Step 2. Explanation for the correct answer

(b) sarcolemma   

• Sarcolemma is the sheath or cell membrane present around the striated muscle fibre.
• The sarcolemma is the plasma membrane of the muscle cell and is surrounded by basement membrane and endomysial connective tissue.

Step 3. Explanation for the incorrect answer

a. myofibril 

• A myofibril is a basic rod-like organelle of a muscle cell. Skeletal muscles are composed of long, tubular cells known as muscle fibers, and these cells contain many chains of myofibrils. 

c. sarcoplasm 

• Sarcoplasm is the cytoplasm of a muscle fibre. It is a water solution containing ATP and phosphagens, as well as the enzymes and intermediate and product molecules involved in many metabolic reactions.

d. myofilament 

• Myofilaments are the three protein filaments of myofibrils in muscle cells. The main proteins involved are myosin, actin, and titin.