To estimate the prevalence of vitamin D deficiency (25(OH)D) <50 nmol/L among recently arrived immigrants from Africa and Asia in Oslo, and to explore 25(OH)D levels according to origin, gender and age.
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.
Flowers and pollinating insects are examples of <span>coevolution. </span>
