Question

1. transverse tubules

(a) transmit action potentials into the muscle cell interior.
(b) store calcium ions.
(c) store synaptic vesicles filled with ach.
(d) connect actin and myosin.

Explanation:

Transverse tubules (T - tubules) are invaginations of the muscle cell membrane. Their main function is to transmit action potentials from the cell surface deep into the muscle cell interior, which synchronizes muscle contraction. The sarcoplasmic reticulum stores calcium ions, synaptic vesicles filled with ACh are in the axon terminals of motor neurons, and cross - bridges connect actin and myosin.

Answer:

A. transmit action potentials into the muscle cell interior