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)thin and thick filaments slide further away from each other
D)thin and thick filaments slide past each other to get closer together

Question

Quizplus · Accepted Answer

The sliding-filament model states that during muscle contraction, the thin filaments slide past the thick filaments, causing the sarcomere to shorten. Therefore, the best choice is D, which says that thin and thick filaments slide past each other to get closer together. A and B are incorrect because only one type of filament (either thin or thick) slides across the ends of the sarcomere, while C is incorrect because the filaments do not slide further away from each other.

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