Question

question 41
myofibrils and composed primarily of:
a troponin
b tropomyosin
c actin and myosin
d atp & adp

Explanation:

Myofibrils are the basic units of muscle fibers. They are composed of thick and thin filaments. The thick filaments are mainly made of myosin, and the thin filaments are mainly made of actin. Troponin and tropomyosin are regulatory proteins associated with the thin filaments but are not the primary components. ATP (adenosine triphosphate) and ADP (adenosine diphosphate) are involved in energy transfer in muscle contraction but are not structural components of myofibrils.

Answer:

C. actin and myosin