Question

The trunk of a tree shrinks during day time due to

• A. Rapid translocation of food
• B. Transpiration induced tension
• C. Rapid growth in day hours
• D. Light induced elongation of plant

Answer 1

The correct option is B Transpiration induced tension

Transpiration is loss of water in vapour form, usually through stomata but it can also occur through general surface. During day time some of the living cells in parenchyma and secondary phloem can lose water and shrink. Even though it will not result in major loss of water, because living cells are few in woody trunk nevertheless it can lead to marginal shrinkage in trunk.