The dark band present on a myofibril is known as:

Analogy type questions:
$(1)$ Red muscle fibers / White muscle fibers have fewer mitochondria but more sarcoplasmic reticulum.
$(2)$ When nerve impulses reach the neuromuscular junction,acetic acid / acetylcholine neurotransmitter is released.

In a contracted skeletal muscle fibre,

$A-$ Actin filaments occur in two forms: the monomeric $G$-actin and the polymeric $F$-actin.
$R-$ Tropomyosin is a rod-shaped fibrous protein. Tropomyosin forms two helical strands,which are wrapped around the $F$-actin filaments.

The backward bending of the shank is worked out by

Which of the following structures contract and relax rhythmically to produce movement?