Question

Guttation is the process of exudation of water and minerals from plants through

• A. stomata
• B. hydathodes
• C. lenticels
• D. root hairs

Answer 1

The correct option is B hydathodes

Guttation is exudation or loss of xylem sap i.e. water and minerals, from a leaf through the openings known as hydathodes.
Hydathodes are present at the terminal ends of the veins at the margins and apices of leaves.
Root pressure is responsible for guttation. The positive hydrostatic pressure developed in the xylem of the root is called root pressure.
It pushes the water column up and it can be clearly seen in small plants in the margins of their leaves.
Since it relies on pressure it is not seen in tall trees as the pressure required to push the xylem sap out will be too high.
It is usually observed in herbaceous plants like grasses during night and early morning due to low evaporation and high atmospheric moisture.

Stomata are openings found on the surface of the leaves that are open during the day and closed at night. These are responsible for exchange of gases and transpiration.

Lenticels are pores found on the bark or stem, and in some plants even in roots or fruits. These remain open all the time and help in exchange of gases and transpiration.