Cell membranes are said to be selectively permeable because they
A) allow the free passage of some materials and restrict the passage of others.
B) allow the passage of materials in one direction but not the other.
C) permit the passage of most materials but not of water.
D) Cell membranes are NOT normally selectively permeable.

Question

Quizplus · Accepted Answer

Cell membranes have the ability to control what substances enter and exit the cell. This selective permeability allows some materials, such as oxygen and glucose, to freely pass through the membrane, while other materials, such as large molecules and charged ions, are restricted from entering or exiting the cell.

Cell Membranes Are Said to Be Selectively Permeable Because They