Which of the following describes fat-soluble vitamins?

A. They form coenzymes that participate in the metabolism of carbohydrates, fat, and protein.
B. Excesses are excreted in the urine.
C. They are absorbed directly from the GI tract into the blood via the hepatic portal vein.
D. They are readily stored in the body.

the answer that best describes the relative refractory period in the neuron is the resting membrane potential is restored, but concentrations of sodium and potassium are not restored to their original state.

the refractory period is the time during which another stimulus given to the neuron will not lead to a second potential. thus, because na+ channels are inactivated during this time, additional depolarizing stimuli do not lead to new action potentials.  

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answer; the correct answer is conflict- related aggression; +

genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).