[Campbell Biology P.1181] The passage mentions an interesting evolutionary adaptation in the ... | Practice Question

The passage mentions an interesting evolutionary adaptation in the muscles that hold a clam shell closed, allowing them to remain contracted for as long as a month with only a low rate of energy consumption. Which of the following best describes the molecular basis for this adaptation?

  • A: Presence of fast-twitch muscle fibers.
  • B: A stretch-activated mechanism for sustained contraction.
  • C: Modification of certain proteins that allows them to remain contracted.
  • D: A very high rate of ATP hydrolysis to maintain tension.

Explanation

The passage directly states: 'Another interesting evolutionary adaptation has been discovered in the muscles that hold a clam shell closed. Modification of certain proteins in these muscles allows them to remain contracted for as long as a month with only a low rate of energy consumption.'