Question

scenario 7: a plant cells journey
a plant biologist is studying a single plant cell under a microscope. to understand how the cell membrane helps maintain homeostasis, the biologist places the cell in three different beakers, each containing a solution with a different concentration of solutes. the cells membrane, which is selectively permeable, must regulate the movement of substances in and out of the cell to keep it in a healthy, stable state.
based on the fluid - mosaic model, how does the cell membrane use both passive and active transport to move substances, and what is the key difference between these two processes?
both passive and active transport require energy, but active transport moves substances down a concentration gradient
passive transport requires energy to move substances against a concentration gradient, while active transport does not require energy
passive transport moves substances across the membrane without energy, while active transport moves substances against a concentration gradient by using energy
passive transport is used for large molecules, while active transport is used for small ions

Explanation:

Passive transport is the movement of substances across the cell - membrane from an area of higher concentration to an area of lower concentration without the use of energy. Active transport moves substances against their concentration gradient (from low to high concentration) and requires energy input, usually in the form of ATP.

Answer:

C. Passive transport moves substances across the membrane without energy, while active transport moves substances against a concentration gradient by using energy