Question

unit 1 cumulative test (characteristics of life, biomolecules, cell struc
6 of 42

the diffusion of water across a selectively permeable membrane is called

facilitated diffusion

osmosis

exocytosis

active transport

Explanation:

To solve this, we analyze each option:

• Facilitated diffusion: Movement of molecules (not water specifically) across a membrane via protein channels.
• Osmosis: Defined as the diffusion of water across a selectively permeable membrane.
• Exocytosis: Process of vesicles fusing with the membrane to release substances out of the cell.
• Active transport: Movement of molecules against concentration gradient, requiring energy.

So the correct term for water diffusion across a selectively permeable membrane is osmosis.

Answer:

B. osmosis (assuming the second option is labeled as B, with the option text "osmosis")