AP BIOLOGY

Detailed explanation-1: -The process of guttation occurs when the roots of a plant absorb water from the soil. This creates a pressure inside the plant-root pressure, and the water is forced out through the hydathodes. As this process occurs, the water picks up chemicals and is no longer simply water; it’s called xylem sap.

Detailed explanation-2: -Guttation usually occurs during periods of active growth when conditions favour more water absorption and less transpiration. Due to the high root pressure, water is forced out into the intercellular space and flows out of the hydathodes.

Detailed explanation-3: -As pressure builds up within the xylem due to osmotic water uptake, the xylem solution is forced upward to the leaves by mass flow. Root pressure can result in the loss of liquid water from the leaves during times of low transpiration.

Detailed explanation-4: -The driving forces for water flow from roots to leaves are root pressure and the transpiration pull. Root pressure is the lesser force and is important mainly in small plants at times when transpiration is not substantial, e.g., at nights.

Detailed explanation-5: -As roots take up fertilizer and other solutes from the soil, these can accumulate in cells inside the endodermis. Then, when transpiration stops at night, pressure may build up as water moves through the endodermis by osmosis. This is when guttation comes into play.