Question

Which of the following statements are correct regarding skeletal muscle?

1. Muscle bundles are held together by collagenous connective tissue layer called fascicle. 
2. Sarcoplasmic reticulum of muscle fibre is a store house of calcium ions. 
3. Striated appearance of skeletal muscle fibre is due to distribution pattern of actin and myosin proteins. 
4. M line is considered as functional unit of contraction called sarcomere.

Choose the most appropriate answer from the options given below:

विकल्प

• B and C only

• A, Cand D only

• C and D only

• A, B and C only

Answer 1

B and C only

Explanation:

Located in muscle cells, the sarcoplasmic reticulum is a specialised version of the endoplasmic reticulum designed to store and release calcium. Skeletal muscle looks striated because of the organised, repeating layout of actin and myosin filaments, which form light and dark bands. These muscles are organised into bundles called fascicles, encased in a connective tissue known as perimysium. Finally, the sarcomere serves as the primary unit of contraction, with the M line acting as a protein support to stabilise its centre.