sarcomere
Sarcomere
The sarcomere is the smallest contractile unit of muscle.
a cell
The smallest contractile unit of a muscle fiber is the sarcomere.It is composed of contractile myofilaments known as actin and myosin.
Muscles always contract entirely i.e. every part of the muscle which contains myosin and actin (contractile proteins) is able to contract and does contract almost simultaneously.
The smallest contractile unit of individual muscle fibers is called a sarcomere. Sarcomeres are made up of overlapping thick and thin filaments that slide past each other during muscle contraction, generating the force necessary for movement.
The stirrup "bone in the ear"
If you mean the smallest bones, they are the bones of the middle ear: malleus (hammer), incus (anvil), and stapes (stirrup).
The striated is dominate, and cardiac the smallest.
Depends on the distance.
If the photon is having very less frequency (say v=1Hz) ,then the Energy of such photon will be the smallest one. It can be inferred that the smallest unit of light energy will correspond to the smallest frequency of such quanta. But from the uncertainty principle it limits the energy of a quanta.