Question

Transport of materials across the membrane along the concentration gradient but helped by carrier:

• A. Active transport
• B. Facilitated diffusion
• C. Diffusion
• D. Osmosis

Answer 1

The correct option is B

Facilitated diffusion

The correct option is B

Explanation of the correct option:

Option B:

1. The diffusion of hydrophilic substances along the concentration gradient through fixed membrane transport proteins without energy involvement is called facilitated diffusion.
2. Facilitated diffusion is very specific, it allows the cell to select substances for uptake.
3. No ATP is consumed.
4. A concentration gradient must already be present for molecules to diffuse even if facilitated by the proteins.

Explanation of the incorrect option:

Option A:

Active transport uses energy to transport and pump molecules against a concentration gradient.

Option C:

The movement of molecules from an area of higher concentration to an area of lower concentration is called diffusion.

Option D:

Diffusion of solvent from a solution of lower concentration to a solution of higher concentration is called osmosis.

Final answer: The transport of materials across the membrane along the concentration gradient but helped by carrier is called as Facilitated diffusion.