Question

You experimentally apply a toxin to a muscle and find that it does not contract when you electrically stimulate the motor neuron leading to it. You know that this toxin blocks acetylcholine receptors. Therefore, you suspect that the stimulation of contraction is failing because: Group of answer choices

Answer 1

The question provided is not complete as it lacks the group of choices, however the group of choices are given as follows:

A. A contraction fails to occur because an action potential is not generated in the muscle cell.

B. A contraction fails to occur because this toxin directly prevents ion release from intracellular stores.

C. A contraction fails to occur because neurotransmitter release by the motor neuron is blocked at the neuromuscular junction.

D. A contraction fails to occur because this toxin prevents cross bridge formation and thereby directly prevents contraction.

E. C and D are both true

Answer:

The correct answer is option A : A contraction fails to occur because an action potential is not generated in the muscle cell.

Explanation:

A muscle contraction takes place when action potential bring to muscles by nerves, which is traveled with the help of motor neuron and imitated the muscle contraction.

Acetylcholine or Ach is a chemical messenger to bring the nerve impulses between a nerve and a muscle. If the receptor is block with applying toxin muscle will not contract as ACh will not be able to propagate the nerve impulse to the muscle so there will be no action potential.

The correct answer is option A : A contraction fails to occur because an action potential is not generated in the muscle cell.