Which best describes a "myofibril"?
A)It is a single skeletal muscle cell.
B)It is a cylindrical cellular organelle composed of myofilaments.
C)It is a hollow membranous structure that stores calcium.
D)It is composed of a single type of protein and forms cross-bridges.
E)It is a fibrous junction between a muscle cell and a tendon.

Question

Which best describes a "myofibril"?
A)It is a single skeletal muscle cell.
B)It is a cylindrical cellular organelle composed of myofilaments.
C)It is a hollow membranous structure that stores calcium.
D)It is composed of a single type of protein and forms cross-bridges.
E)It is a fibrous junction between a muscle cell and a tendon.

Quizplus · Accepted Answer

A myofibril is a cylindrical subunit of a muscle fiber that is composed of myofilaments, which are protein structures responsible for muscle contraction. It is not a single muscle cell (A), a hollow membranous structure (C), a single type of protein (D), or a fibrous junction (E).

Which Best Describes a "Myofibril