The concentration of sodium and potassium ions inside and outside a nerve cell must be reset each time the transition of a nerve impulse occurs. both ion types are able to move across the nerve cell membrane against the concentration gradient. To maintain these gradients, nerve cells depend directly on the chemical output of which other cell process. mitosis
replication
respiration
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explanation:

the universal gravitation equation. since the gravitational force is directly proportional to the mass of both interacting objects, more massive objects will attract each other with a greater gravitational force. if the mass of one of the objects is doubled, then the force of gravity between them is doubled.

regents of the university of california v. bakke, 438 u.s. 265 (1978), was a landmark decision by the supreme court of the united states. it upheld affirmative action, allowing race to be one of several factors in college admission policy.