Muscle fatigue occurs due to the accumulation of:

The functional unit of the contractile system for a striated muscle is:

How is the meromyosin formed?

Arrange the given steps of muscle contraction in the series of events from first to last.
$I.$ Myosin head binds to the exposed active site on actin to form a cross bridge.
$II.$ The $Z$-line attached to these actin are also pulled inwards,thereby causing shortening of sarcomere,also called contraction.
$III.$ This pulls the attached actin filaments towards the centre of $A$-band.
The correct option is:

$ATP$ binding site is located on the

Identify the correct labels for the parts of the myosin monomer shown in the diagram.