Question

Skeletal muscles show resemblance with visceral muscles in one aspect. It is in
(a) Number of nuclei present in the myofibril.
(b) Presence of actin and myosin filaments.
(c) Shape of the myofibril.
(d) Presence of light and dark bands.

Answer 1

Hint: In vertebrates, there are three kinds of muscles, striated or skeletal, non-striated or visceral, and cardiac or heart muscles. Certain proteins are actively involved in the contraction of muscle fibers in all kinds of muscles.

Complete answer:
Actin filaments and myosin filaments are present in the skeletal muscle as well as in the visceral muscle. Striated muscles are the muscles that bring about the movements of bones in the vertebrate body. They are long cylindrical and unbranched fibers. They are voluntary inaction. They are always seen attached to the skeleton. Visceral muscles are long, spindle-shaped, and unbranched fibers. They are involuntary in action. They exhibit sustained and rhythmic contraction and slow fatigue.

Additional Information: -Muscles form the contractor tissue, concerned with all kinds of bodily movements including locomotion. They serve as the biological system for transducing chemical energy to mechanical energy and mechanical work.
-Visceral muscles are hollow in internal organs, such as the stomach, intestine, blood, vessels, urinary bladder, uterus, ureter, vas deferens, etc.
-Their fibers have no transverse bands or striations. Hence they are also called smooth muscles or unstriped muscles.
So, the correct answer is 'Presence of actin and myosin filaments'.

Note: -Visceral muscles are arranged in different ways. Those on the wall of hollow organs are arranged in sheets or layers, those in the skin are arranged in groups, and those at the base of hair are arranged in bundles, but not in definite fasciculi.
-Functionally, there are two kinds of smooth muscles, namely single-unit smooth muscles and multi-unit smooth muscles.
-Single unit muscles are the smooth muscles whose fibers function in close coordination as a single unit or functional syncytium. Multi-unit smooth muscles are smooth muscles whose fibers are devoid of interconnecting bridges and they function individually as independent units.