Answer:
A. If neither parent expresses the trait, but the offspring does, both parents must be heterozygous for the trait.
Explanation:
If neither parents express the trait is because they are heterozygous and the dominant allele is being expressed over the recessive trait. When parents cross they have 25% of having an offspring that expresses the recessive trait, this means the offspring is a recessive homozygous. In the attached example 25% or 1/4 will have a short stem.
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.
A function of the nucleus is D) Storing genetic material.