$ATP$ase of the muscle is located on:

The actin filament is shown below. Where does $Ca^{++}$ bind during muscle contraction?

Which of the following is the contractile protein of a muscle?

Which of the following statements are false regarding the muscle structure?
$I.$ In the centre of each $I$-band is an elastic fibre ($Z$-line) which bisects it.
$II.$ Thin filaments are firmly attached to the $Z$-line.
$III.$ $M$-line is a fibrous membrane in the middle of $A$-band.
$IV.$ $A$ sarcomere comprises one full $A$-band and two half $I$-bands.

Which of the following is both a structural and functional protein?

During muscular contraction,which of the following events occur?
$(a)$ $'H'$ zone disappears
$(b)$ $'A'$ band widens
$(c)$ $'I'$ band reduces in width
$(d)$ Myosin hydrolyzes $ATP$,releasing the $ADP$ and $\Pi$
$(e)$ $Z$-lines attached to actins are pulled inwards
Choose the correct answer from the options given below.