You should test your hypothesis.
Answer:
The charges inside and outside of the neuron before receiving a stimulus are negative and positive, respectively, which corresponds to the transmembrane rest potential.
Explanation:
Neuron is the specialized cell of the nervous system in charge of transmitting electrical impulses. The generation of a nerve impulse in the form of an electric current is due to a change in the transmembrane potential.
<u>Outside the neuron cell, electrical charges are predominantly positive, and the ion with the highest concentration is sodium. In the intracellular space, a great quantity of proteins provide negative charge, and there is a predominance of potassium ions</u>. Under these conditions, the ionic channels are closed.
For this reason, a neuron at rest, before receiving a stimulus, presents positive charges on the outside and negative charges on the inside, and the membrane potential in this condition is estimated at a value of -65 mV.
Once a stimulus is produced, the ionic channels open and Na+ ions enter the cytoplasm, exchanging them for K+, which implies a change in the membrane potential which, on reaching the threshold, produces an action potential and the nerve impulse is produced.
Answer:
A) Any butterfly allele that allowed milkweed toxin storage would be likely to persist because butterflies that had it were more likely to survive.
Explanation:
Butterflies are natural preys to birds. Over time, some butterflies evolved adaptive strategy such as developing an allele which enables storage of toxin from milkweed as a form of defense mechanism. This stored toxins repel birds from eating the butterflies having this allele giving rise to the survival of these butterflies overtime. Butterflies that had it are likely to be highly favored for survival against predatory birds, while those butterflies without this allele are likely to be heavily preyed upon by birds.
