Which of the following questions can be asked about organisms that live in fresh water Will their bodies take in too much water Can they control their tonicity Can they survive in salt water Will their bodies lose too much water to their environment 12 Which of the following explains why active movement of molecules across membranes must function continuously 13 Why must active transport of molecules across plasma membranes function continuously Diffusion cannot occur in certain cells Diffusion is constantly moving solutes in opposite directions Facilitated diffusion works in the same direction as active transport Not all membranes are amphiphilic 14 How does the sodium potassium pump make the interior of the cell negatively charged by expelling anions by pulling in anions by expelling more cations than it takes in by taking in and expelling an equal number of cations 15 What is the difference between primary and secondary active transport Primary active transport is indirectly dependent on ATP while secondary active transport is directly dependent on ATP Primary active transport is directly dependent on ATP while secondary active transport is indirectly dependent on ATP Primary active transport does not require ATP while secondary active transport is indirectly dependent on ATP Primary active transport is indirectly dependent on ATP while secondary active transport does not require ATP 16 What happens to the membrane of a vesicle after exocytosis It leaves the cell It is disassembled by the cell