PLANT PHYSIOLOGY
TRANSPORT IN PLANT
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Water molecules sticking to each other
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Water molecules sticking to cellulose in xylem walls
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Magnets sticking to a metal wall
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Gravity pulling water down
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Detailed explanation-1: -Xylem tissue is made of millions of tiny tubes made of cellulose. Because water molecules like to stick together (cohesion) and like to stick to the walls of the tubes of cellulose (adhesion), they rise up the tubes all the way from the roots to the leaves.
Detailed explanation-2: -A water drop is composed of water molecules that like to stick together-an example of the property of cohesion. In the picture of pine needles above, the water droplets are stuck to the end of the pine needles-an example of the property of adhesion.
Detailed explanation-3: -Adhesion, which is molecular attraction between “unlike” molecules. In the case of xylem, adhesion occurs between water molecules and the molecules of the xylem cell walls.
Detailed explanation-4: -Water molecules are polar and can form a type of intermolecular association called a hydrogen bond. This cohesive property causes water molecules to be dragged up the xylem towards the leaves in a continuous stream.