69) Diffusion occurs because of random molecular movement.
70) A cell : 1380737.
69) Diffusion occurs because of random molecular movement.
70) A cell wall stops a plant cell from taking in so much water that it will burst.
71) A substance moving down the concentration gradient is an example of active transport.
72) Facilitated diffusion occurs through membrane-bound transport proteins.
73) Facilitated diffusion occurs down a concentration gradient.
74) Active transport moves a substance against the concentration gradient.
75) To move a molecule into a cell against the concentration gradient requires energy.
76) Exocytosis is an example of active transport of a substance into the cell.
77) Phagocytosis is an example of passive transport.
69) Diffusion occurs because of random molecular movement.
70) A cell : 1380737
