Question

A cell membrane regulates which substances can enter and leave the cell based on their size and polarity . Which mode of cell transport is the movement of a substance from a high concentration to an area of lower concentration without the use of protein channels or energy?

• A. Simple diffusion
• B. Facilitated diffusion
• C. Osmosis
• D. Active transport
• E. Isotonic

Answer 1

The correct option is A Simple diffusion

A. Simple diffusion is the net movement of particles of a substance from a region of greater or higher concentration to a region of lower concentration due to their own intrinsic kinetic energy. In simple words, it is a passive movement of molecules along their concentration gradient.

B. Facilitated diffusion is the passive movement of molecules along their concentration gradient with the help of membrane proteins known as channel proteins or carrier proteins.

C. Osmosis is the diffusion of water molecules through a semipermeable membrane along the concentration gradient.

D. In Active transport, molecules are carried from a region of lower concentration to a region of higher concentration against the concentration gradient with the utilisation of ATP.

E. Isotonic solution is a solution with equal solute concentrations to one another and thus, there is no net movement of water.

So, the correct answer is Simple diffusion,