Sarcolemma is the covering of

$A -$ 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.

Cardiac muscle fibers are........

The dark band present on a myofibril is known as:

In muscular hypertrophy,what happens to the muscle cells?

The dark bands ($A$-bands) of a skeletal muscle are known as