How do plant root hair cells absorb dissolved mineral nitrate ions from low concentrations in soil water into high concentrations inside the cell?
Answer and explanation
Correct answer: D. Active transport
- Step 1: When internal ion concentrations exceed external soil levels, diffusion cannot move ions inward. Step 2. Root cells employ active transport carrier proteins in the plasma membrane, consuming ATP from cellular respiration to pump nitrates against the gradient. Answer: Active transport. Why not the others: Diffusion and osmosis are passive processes that only operate down gradients.
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