The sliding filament theory can be best explained as:

Hypertrophy of muscle is

Define the following terms:
$(1)$ Intercalated disc
$(2)$ Neuromuscular junction

Select the correct statement with reference to muscle structure.
$I.$ Each myosin is a polymerized protein.
$II.$ Many meromyosin constitute one thick filament (myosin).
$III.$ Each meromyosin's tail is called heavy meromyosin $(HMM)$ and head is called light meromyosin $(LMM)$.
$IV.$ The globular head is an active $ATPase$ enzyme and has binding sites for $ATP$ and active sites for actin.
Choose the option with correct statements.

The largest smooth muscle is present in:

Contractile proteins are found in