(85 points! ) a nerve signal is like a wave. how does this work?

a: an electrical wave moves down the axon by electrons moving from the place the signal started to the place it ends up.
b: a wave of reversal of the negative electrical potential inside the cell passes along the axon with ions moving in and out of the axon.
c: a wave of movement passes down the axon, in which the whole axon moves sideways in one place and then the next.
d: the density of the cytoplasm inside the axon changes from one place to the next as the signal moves along the axon.

What type of genetic drift would be simulated if all the beans that were not selected died out?

Aresearcher designed an investigation to test what effect eating different types of food would have on blood insulin levels. she selected 10 male subjects who were all 25 years of age and in good health. the experiment took place over 3 days. at 8: 00 a.m. on each day, the subjects ate a meal consisting of only 1 type of food. they had their blood insulin levels measured after consuming the meal. on day 1 they ate a high fat diet, on day 2 they ate a high protein diet, and on day 3 they ate a high sugar diel what is the independent variable in this experiment? a the age of the subjects b the blood insulin level c the type of food consumed d the time of day the meal was consumed

_tissues respond quickly to outside stimuli a) epithelia b)nervous c)muscular d)muscular and nervous