Question

In which method of transport in plasma membrane, a carrier molecule is not required?

• A. Active transport
• B. Facilitated diffusion
• C. Simple diffusion
• D. Na${}^{+}$- K${}^{+}$ pump

Answer 1

The correct option is C Simple diffusion

Simple diffusion occurs according to the differences in the concentration of molecules or along the concentration gradient. Diffusion means the transport of materials from a region of higher concentration to a region of lower concentration. It does not require carrier molecules. Thus, the correct answer is option C.