In order to maintain its homeostasis, human cells must have a higher concentration of sodium ions outside the cell than inside the cell. in addition, the concentration of potassium ions must be higher inside the cell than outside the cell. which of the following forms of cellular transportation human cells maintain their sodium and potassium concentration?
a. diffusion
b. a cell membrane pump
c. osmosis
d. passive transport

Read this summary of a scientific theory: "cells are the most basic structural and functional units of life. all living organisms are made up of one or more cells. all cells that are alive in the world today came from pre-existing cells." which of the following would require this theory to be modified? -a.) a survey finds that a majority of people believe viruses carry out the basic processes of life. -b.) a prominent scientist says she feels strongly that one day the theory will be challenged by life on other planets. -c.) the dna of unicellular and multi-cellular organisms is shown to have many fundamental similarities. -d.) scientific observations show that microscopic organisms living in the deep ocean are not made up of cells.