Voluntary muscle is present in

In a contracted skeletal muscle fibre,

What are the characteristic features of skeletal muscles?

The Krause membrane or $Z$-line is a structure in a myofibril that separates two adjacent:

Select the correct option for the following statements:
$(i)$ The most important respiratory organ in frogs is the skin / lungs.
(ii) Skeletal muscle / Cardiac muscle exhibits rhythmic contraction.

The $H$-zone in the skeletal muscle fibre is due to