$\text{ATP}$ase is located in $:-$

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

Proprioceptors are present in . . . . . . .

During muscle contraction,$(P)$ get reduced whereas $(Q)$ retain the length. Here $P$ and $Q$ are $-$

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:

Select the correct option regarding the components of myosin.