Which statement best explains the cohesion-tension theory?
Answer and explanation
Correct answer: A. Evaporation from leaves creates tension that pulls a cohesive water column up the xylem
- Step 1: Transpiration lowers water potential in leaf mesophyll. Step 2. Cohesion between water molecules transmits the pull down the xylem. Answer: Evaporation from leaves creates tension that pulls a cohesive water column up the xylem. Why not the others: xylem is dead and cannot pump; sucrose loading drives phloem flow; root pressure cannot lift water to great heights.
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