Identify the parts $A$ and $B$ from the given diagram.

The human skeletal system consists of:

Which of the following is not a function of locomotion?

In children,the bones are more flexible and less brittle because their bones have:

Write true or false. If false,correct the statement to make it true.
$(a)$ Actin is present in thin filament.
$(b)$ $H$-zone of striated muscle fibre represents both thick and thin filaments.
$(c)$ Human skeleton has $206$ bones.
$(d)$ There are $11$ pairs of ribs in man.
$(e)$ Sternum is present on the ventral side of the body.

We swing our arms while walking for $......$.