Question

multiple choice question
during the contraction of muscle cells, which fiber is used?
microtubules
actin
intermediate filaments
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Explanation:

Muscle contraction is mainly mediated by the interaction of actin and myosin filaments. Microtubules are involved in cell - division and intracellular transport, not muscle contraction. Intermediate filaments provide structural support but are not directly involved in muscle contraction. Actin is one of the key components in the sliding - filament theory of muscle contraction.

Answer:

B. Actin