Question

multiple choice 1 point
how does the selectively permeable nature of the cell membrane contribute to maintaining homeostasis?
by allowing all substances to pass freely into and out of the cell.
by preventing all substances from entering or leaving the cell.
by regulating the movement of substances into and out of the cell based on their size, charge,
and concentration.
by actively transporting all substances against their concentration gradients

Explanation:

The cell membrane is selectively permeable. It regulates the movement of substances (based on size, charge, etc.) into and out of the cell. This regulation helps in maintaining a stable internal environment (homeostasis). Allowing all substances freely (wrong as it's selective), preventing all (wrong as some do pass), active transport of all (energy - intensive and not for all) are incorrect.

Answer:

By regulating the movement of substances into and out of the cell based on their size, charge, and concentration.