Question

A muscle cramp is a sudden, painful contraction of a muscle, during which movement is difficult. What is happening at the cellular level during a muscle cramp?

A.
The motor neuron does not send a signal, so the muscle cannot relax.
B.
Myosin and actin do not fully detach, so the muscle cannot relax.
C.
The proteins in the myofibrils become denatured, preventing relaxation.
D.
A lack of calcium causes the sarcomeres to lock together, preventing relaxation.

Answer 1

Answer B

Myosin and actin do not fully detach, so the muscle cannot relax.

Answer 2

I think (b) is current ans