The primary difference between retrograde and anterograde amnesia concerns whether:

a. the to-be-remembered event occurred before of after damage to the hippocampus.
b. forgetting is due to retroactive or proactive inteference.
c. there is a disruption in consolidation or reconsolidation.
d. procedural or declarative memory is involved.

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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affects the water bodies: excessive use of fertilizers causes eutrophication. the fertilizers which are used on plants affect the quality of land on which it is used, further causing erosion of soil. the fertilizers used on plants contain harmful chemical fumes which affect the environment.

the missing space is phylum

b. to discover aspects of the natural world.

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