Movement and accumulation of ions across a membrane against their concentration gradient can be explained by
Answer: (D) Active transport. Answer: (D) Active transport Solution: Movement of a few ions or molecules across the membrane against their concentration gradient (from lower to higher concentration) is an energy-dependent process in which ATP is utilised, and is called active transport (e.g., Na+/K+ pump).
- A.Osmosis
- B.Facilitated Diffusion
- C.Passive Transport
- D.Active transport✓
Correct Answer
(D) Active transport
Solution & Explanation
Answer: (D) Active transport Solution: Movement of a few ions or molecules across the membrane against their concentration gradient (from lower to higher concentration) is an energy-dependent process in which ATP is utilised, and is called active transport (e.g., Na+/K+ pump). Osmosis, facilitated diffusion and passive transport all proceed along (down) the concentration gradient without energy expenditure. NCERT Reference: Ch 8, p.94, lines 22-25: "concentration gradient, i.e., from lower to the higher concentration. Such"