Question

list the following structures in order from smallest to largest.
(1) muscle fiber
(2) myofilament
(3) myofibril
(4) muscle fasciculus
a 2, 3, 1, 4
b 3, 1, 4, 2
c 4, 2, 3, 1
d 1, 2, 3, 4
e 2, 1, 4, 3

Explanation:

• Myofilaments (such as actin and myosin filaments) are the smallest structural units involved in muscle contraction.
• Myofibrils are made up of multiple myofilaments.
• Muscle fibers (muscle cells) contain numerous myofibrils.
• Muscle fasciculus is a bundle of muscle fibers.

Answer:

A. 2, 3, 1, 4