Process of water exudation fom hydathodes is known as:

Question

Accepted Answer

The correct option is 1:

Guttation is the process of water exudation in the form of liquid droplets from the margins or tips of leaves, primarily through specialized pores called hydathodes. This phenomenon typically occurs when transpiration (water loss as vapor from stomata) is low, usually during the night or in humid conditions, and root pressure is high. The roots continue to absorb water, building up pressure within the xylem. Since the stomata are closed (or transpiration is negligible), this excess water is forced out through the hydathodes, which are structurally different from stomata as they are always open. The water exuded during guttation is not pure water but contains dissolved minerals and salts from the plant sap.

The incorrect option is 2: Transpiration. Transpiration is the process of water vapor loss from the aerial parts of the plant, mainly through stomata, into the atmosphere. Unlike guttation, transpiration involves water being lost as a gas, and it is a crucial process for cooling the plant and driving the upward movement of water and nutrients.

The incorrect option is 3: Evaporation. Evaporation is the general process by which a liquid changes into a gas, typically from a surface. While transpiration involves evaporation of water from leaf surfaces, evaporation itself is a physical process, not a specific biological process of water exudation from hydathodes in plants.

The incorrect option is 4: Bleeding. Bleeding, also known as "sap flow," refers to the exudation of plant sap from a cut or wounded plant part. This is a general response to injury and involves the release of xylem or phloem sap, which is different from the specific process of water exudation from hydathodes under high root pressure in intact plants.