Transport in Plants Question 1
1. The process responsible for facilitating loss of water in liquid form from the tip of grass blades at night and in early morning is [2020]
(a) Root pressure
(b) Imbibition
(c) Plasmolysis
(d) Transpiration
Show Answer
Answer : a
Hints & Solutions
(a) Root pressure is positive hydrostatic pressure. It develops in tracheary element at night and in early morning. Root pressure is caused by active distribution of mineral nutrient ions into the root xylem. Without transpiration to carry the ions up the stem, they accumulate in the root xylem and lower the water potential. Water then diffuses from the soil into the root xylem due to osmosis.
