Question

The striated appearance of a myofibril is due to the distribution pattern of

• A. Actin and myosin.
• B. Fascides.
• C. Troponin.
• D. Meromyosin.

Answer 1

The correct option is A Actin and myosin.

The myofibril appears striated as they are composed of actin and myosin filaments, repeated in units called sarcomere, which is the basic functional unit of the muscle fiber. The sarcomere is responsible for the striated appearance of muscle.The actin is thin filament and myosin is thick filaments.

A muscle fascicle is a bundle of skeletal muscle fibers surrounded by perimysium.

Troponin is a globular protein complex involved in muscle contraction.It occurs with tropomyosin in the thin filament of muscle fiber.

Meromyosin are subunits of myosin, the thick filament.

Hence, the correct answer is option A.