AP BIOLOGY

Detailed explanation-1: -This grip-like characteristic that water molecules form causes capillary action, the ability of a liquid to flow against gravity in a narrow space. An example of capillary action is when you place a straw into a glass of water.

Detailed explanation-2: -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.

Detailed explanation-3: -Capillary action helps bring water up into the roots. But capillary action can only “pull” water up a small distance, after which it cannot overcome gravity. To get water up to all the branches and leaves, the forces of adhesion and cohesion go to work in the plant’s xylem to move water to the furthest leaf.

Detailed explanation-4: -In the xylem vessels, water molecules are strongly attracted to each other and exhibit a “stickiness” called cohesion that is due to the formation of hydrogen bonds between different water molecules. The “stickiness” between water molecules and the xylem vessel walls is called adhesion.