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.
The answer is D all forms of life depend on each other for survival
Flatworms-In the life cycle of trematode flukes of the subclass Digenea, mollusks (mostly snails) serve as the intermediate host. Fertilized eggs usually hatch in water. The first larval stage, the miracidium, generally is free-swimming and penetrates a freshwater or marine snail, unless it has already been ingested by one.
Roundworms-Roundworms can complete their life cycle in immature dogs, but as the pup's immune system matures (usually by 6 months of age), the larval stages of the roundworm will become arrested and will encyst (become enclosed in a cyst) in the pup's muscles. They can remain encysted in the dog's tissues for months or years.