The largest muscle in the human body is:

The dark band present on a myofibril is known as:

Discuss the role of $Ca^{2+}$ ions in muscle contraction. Draw neat sketches to illustrate your answer.

In a skeletal muscle fiber,what is the $H$-zone?

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.

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