The main difference between active and passive transport across cell membrane is :
Answer: (B) Passive transport requires a concentration gradient across a biological membrane whereas active transport requires energy to move solutes. Answer: (B) Passive transport requires a concentration gradient across a biological membrane whereas active transport requires energy to move solutes Solution: Passive transport moves molecules along the concentration gradient (higher to lower) without any requirement of energy, so it depends on the gradient existing across the membrane.
- A.Passive transport is non-selective wherease active transport is selective
- B.Passive transport requires a concentration gradient across a biological membrane whereas active transport requires energy to move solutes✓
- C.Passive transport is confined to anionic carrier proteins whereas active transport is confined to cationic channel proteins
- D.Active transport occurs more rapidly than passive transport
Correct Answer
(B) Passive transport requires a concentration gradient across a biological membrane whereas active transport requires energy to move solutes
Solution & Explanation
Answer: (B) Passive transport requires a concentration gradient across a biological membrane whereas active transport requires energy to move solutes Solution: Passive transport moves molecules along the concentration gradient (higher to lower) without any requirement of energy, so it depends on the gradient existing across the membrane. Active transport instead moves ions/molecules against the concentration gradient and is an energy-dependent process in which ATP is utilised. The distinction is thus gradient-driven (passive) versus energy-driven (active). NCERT Reference: Ch 8, p.94, lines 13-15 and 23-25: "briefly across the membrane without any requirement of energy and this"