An example of osmosis in plants is the

Step 1: Analyze the question We need the example that is truly osmosis in plants.

Step 2: The concept Osmosis is the movement of water molecules from a region of higher water potential (dilute solution) to a region of lower water potential (concentrated solution) through a selectively permeable membrane.

Two things must be present: water moving down a water potential gradient, and a selectively permeable membrane (such as a cell membrane).

Step 3: Check each option

• A. Movement of water through the xylem: This is mainly due to transpiration pull, cohesion and adhesion, and root pressure. Xylem vessels are dead, hollow tubes with no living membrane, so it is mass flow, not osmosis.
• B. Loss of water vapour from the stomata: This is transpiration, which involves evaporation and diffusion of water vapour (a gas) into the air. It is not osmosis.
• C. Translocation of food through the phloem: This is the transport of dissolved sugars, which is an active process (mass flow), not osmosis.
• D. Absorption of water from the soil by the root: Soil water is dilute, with higher water potential. The root hair cell sap is more concentrated, with lower water potential. Water therefore moves from the soil into the root hair cell across its selectively permeable cell membrane. This is osmosis.

Step 4: Answer The correct option is D.

Tip: When you see "osmosis in plants", think of root hair cells, the classic example. Remember that the xylem is for transport (mass flow), the stomata are for transpiration (evaporation and diffusion), and the phloem is for translocation. Only the root hair absorbs water across a living membrane.