Myelinated axons have gaps every so often for sodium ions to enter and refresh the action potential. what is one called?

the generally accepted parts of modern cell theory include: all known living things are made up of one or more cells. all living cells arise from pre-existing cells by division. the cell is the fundamental unit of structure and function in all living organisms.

the answers are a and c

the answer is d p: cell, q: organ, r: organ system, s: tissue