Striated muscle fibers are found in......

Sarcolemma is the covering of

Which of the following ions is necessary for the contraction of muscles and nerve impulse transmission?

Myosin head separates from actin when:

Name the ion responsible for unmasking of active sites for myosin for cross-bridge activity during muscle contraction.

$A -$ Calcium ions $(Ca^{2+})$ activate the interaction between myosin and actin filaments.
$R -$ The cross-bridge is formed in the presence of $ATP,$ and the breaking of the cross-bridge also requires the binding of a new $ATP$ molecule.