Structure that provides nutrients to the developing embryo in
oviparous organisms​

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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the corpus luteum secretes estrogens and progesterone. the latter hormone causes changes in the uterus that make it more suitable for implantation of the fertilized ovum and the nourishment of the embryo. if the egg is not fertilized, the corpus luteum becomes inactive after 10–14 days, and menstruation occurs.

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