According to the sliding-filament model of muscle contraction,a sarcomere contracts when its ______.
A) thick filaments slide across the ends of the sarcomere
B) thin filaments slide across the ends of the sarcomere
C) thick filaments slide toward each other across its thin filaments
D) thin filaments slide past its thick filaments

Question

Quizplus · Accepted Answer

The sliding-filament model states that muscle contraction occurs when the thin filaments slide past the thick filaments, causing the sarcomere to shorten. Choice A is incorrect because the thick filaments do not slide across the ends of the sarcomere. Choice B is also incorrect because the thin filaments do not slide across the ends of the sarcomere. Choice C is incorrect because the thick filaments do not slide towards each other across the thin filaments.

According to the Sliding-Filament Model of Muscle Contraction,a Sarcomere Contracts