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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i believe your answer would be c.. : )

osteogenesis imperfecta (oi) refers to a congenital ailment of bones. in the condition, the bones become brittle or fragile. this ailment is a general result of the defect or mutations in the genes (colia1 or colia2). this mutation results in imperfect collagen formation either in quantity or quality wise.  

there are eight kinds of oi defects, and each kind varies with certain distinctions in symptoms. the usual symptoms include frequent bone fractures, loss of hearing in infants, protruding eyes, discoloration of the white in the eyes, respiratory issues, loosening of the joints, short stature, and other symptoms.