[Campbell Biology P.1186] Referring to the diagrams of muscle contraction, what key event acc... | Practice Question

Referring to the diagrams of muscle contraction, what key event accurately describes the transition from a relaxed to a fully contracted sarcomere?

  • A: The thick and thin filaments themselves shorten significantly, leading to sarcomere contraction.
  • B: The sarcomere lengthens as the thin filaments are pulled away from the center.
  • C: The sarcomere shortens as thick and thin filaments slide past each other, increasing their overlap.
  • D: The physical arrangement of filaments remains the same, but the muscle cell swells.

Explanation

As described by the sliding filament model of muscle contraction, the sarcomere shortens due to the thick and thin filaments sliding past each other, increasing their overlap, without the filaments themselves shortening. This is clearly depicted in the diagram showing the transition from relaxed to fully contracted muscle.