Question

1. cells need to bring in molecules to carry out cellular processes. often, this requires moving the molecules across the cell membrane against the concentration gradient. how do these molecules get into the cell?

a. passive transport by diffusion
b. active transport using atp
c. passive transport by osmosis
d. phagocytosis

Explanation:

Passive transport (diffusion and osmosis) moves molecules down the concentration gradient. Phagocytosis is for engulfing large particles. Active transport uses ATP to move molecules against the concentration gradient.

Answer:

B. active transport using ATP