When a plant cell is placed in surroundings containing a greater solute concentration than inside the cell, what happens to the cell? A. plasmolysis. B. the cell becomes flaccid. What type of transport process is the movement of a solute across a membrane, against its concentration gradient, and which requires energy? A. Active transport. B. Diffusion. C. Osmosis. D. facilitated diffusion. What type of transport process is the passive movement of a solute across a membrane, down its concentration gradient, and which requires transport proteins? A. Active transport. B. Diffusion. C. Osmosis. D. facilitated diffusion. What type of transport process is the passive movement of a solute across a membrane and down its concentration gradient? A. Active transport. B. Diffusion. C. Osmosis. D. facilitated diffusion.