CBSE Class 10 Science 2023 · Paper 31/2/2 · Question 22

(a) If the xylem is removed, water and dissolved minerals can no longer be conducted from the roots to the stem and leaves. The leaves go on losing water by transpiration, so they wilt; photosynthesis cannot continue for want of water; and the plant, at least all of it above the removed part, dies. (b) When we are injured and start bleeding, the platelets in the blood gather at the injury and help the blood to clot there. The clot plugs the leak, which stops further loss of blood and the fall in pressure that would reduce the efficiency of the pumping system.