Both proteins,actin and myosin,are arranged in a rod-like structure in the muscles:

Arrange the following steps of muscle relaxation in the correct chronological sequence:
$I.$ $Ca^{2+}$ ions are pumped back to the sarcoplasmic reticulum.
$II.$ $Z$-lines return to their original position.
$III.$ Masking of actin filaments occurs.
$IV.$ Relaxation of muscles.

Relaxation of the muscle takes place due to
$I.$ Pumping of $Ca^{2+}$ ions into the sarcoplasmic reticulum
$II.$ Presence of $ATP$
$III.$ Conformational changes in troponin and masking of the actin filament
Which of the following options contains the correct statements?

Which of the following are the special properties of muscles?

Sarcoplasmic reticulum is related with

The set of ions necessary for muscle contraction is