Why does sodium and potassium ions need a protein pump to pass through the cell membrane? A. The ions have a charge and cannot pass directly through the cell membrane.
B. The ions are moving against the concentration gradient.
C. Energy is needed to move the ions.
D. All of the above.

Which group of protists would be most likely to have cilia as adults and why? (1 point)the sporozoan protists would since they have to spread their spores around.the heterotrophic protists would since they use them to gather food.the parasitic protists would since they need to find other organisms to attack.the autotrophic protists would since they must move to find light.