Which type of muscle is multinucleated during its functional state?

Titan filament connects

During muscle contraction,which of the following events occurs?

In the resting state,a subunit of troponin masks the active binding sites for .......... on the .......... filaments.

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:

The structural and functional unit of the striated muscle fibre is called