Q: What term describes a way that small molecules or ions move across the cell membrane without input of energy by the cell?


Read this paragraph and choose the correct option from the provided answers:

Passive transport is a way that small molecules or ions move across the cell membrane without input of energy by the cell. The three main kinds of passive transport are diffusion (or simple diffusion), osmosis, and facilitated diffusion. Simple diffusion and osmosis do not involve transport proteins. Facilitated diffusion requires the assistance of proteins.

 Choices:

- physical transport

- impassive transport

- immune transport

- passive transport


A:
passive transport