The sensation of fatigue in the muscles after prolonged strenuous physical work is caused by

Select the correct option regarding the components of myosin.

Which muscle component is the smallest among the given options?

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 mineral element is essential for muscle contraction?

Sliding filament theory can be best explained as