Same chapter3 marksDifficulty: Medium
Distinguish between the apoplast and the symplast pathways of water movement.
Transport in Plants and Mineral Nutrition
3 marksDifficulty: Medium
Explain the cohesion-tension theory of the ascent of sap.
Original Khojo Papers practice question — not from a past board paper.
Answer
Water evaporating from the mesophyll cells during transpiration lowers the water potential there and creates a pull. Water molecules cling to one another by cohesion and to the walls of the xylem by adhesion, forming a continuous column from root to leaf, so the pull is transmitted right down and water is drawn up.
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
Root pressure contributes only a little and cannot account for the height of a tall tree.
Related questions
From the same topic and chapter, at a similar level.
Same chapter3 marksDifficulty: Medium
Define water potential, solute potential and pressure potential, and state their relation.
Transport in Plants and Mineral Nutrition
Same chapter3 marksDifficulty: Medium
Name three macronutrients and three micronutrients required by plants and state one deficiency symptom.
Transport in Plants and Mineral Nutrition
Same subject3 marksDifficulty: Medium
State three differences between gymnosperms and angiosperms.
Plant Kingdom
Same subject3 marksDifficulty: Medium
State three characteristics of bryophytes and name one example.
Plant Kingdom
Same subject3 marksDifficulty: Medium
What are viruses, and why are they placed outside the five-kingdom system?
The Living World and Biological Classification