Question

Guttation occurs only in
(a) Hydrophytes
(b)Mesophytes
(c) Mangroves
(d)Marshy plants

Answer 1

Hint These are the largest group of terrestrial plants that live in a moderate climate, needs only a moderate amount of water and the soil in which they grow is not dry and not too wet.

Complete answer:
Guttation occurs only in mesophytes. Guttation is the process of secretion of drops of xylem sap from hydathodes on the tips or edges of leaves of some vascular plants, such as grasses, and several fungi. It generally happens at night and early morning.
Mesophytes are terrestrial plants that show the features of both hydrophytes and xerophytes. These plants grow in a condition where the concentration of water and temperature is not too high and not too low. Mesophytes involve grasses and herbs and also some woody plants.

Additional Information:
-In mesophytes, the roots are highly branched and grow deep inside the soil to provide support to the plant. They efficiently absorb water and minerals from the surrounding soil. They bear root hairs and root caps also.
-The leaves of mesophytes are comparatively thin and large in size so that it has increased surface area for absorption of light energy to increase the rate of photosynthesis.
-During the day time transpiration decreases the speed of guttation, guttation slows also thanks to quick evaporation due to excessive sunlight. Water can rise up to two feet on its own through the xylem tissues of the plant.
-It is an important process of removal of extra water from plants, in this way plants balance the amount of water they absorb.
-Guttation is caused due to root pressure and also it causes permanent loss of water. It is not dew. Dew condenses onto the plant surface from the atmosphere.
-By guttation and transpiration, plants release the excess absorbed water, this cools the plant and the surrounding atmosphere as well. When the surrounding atmosphere becomes hot, this cooling takes place.

So the correct answer is 'Mesophytes'.

Note:
-The process in which plant pores secrete droplets of water is known as guttation and it occurs in moist conditions.
-Guttation commonly occurs in mesophytes at night when transpiration is not taking place due to closed stomata.
-In rare cases, guttation bacteria can grow on droplets and may be pulled back to the leaf when the sun comes up, resulting in disease infection.
-Hydathodes is a kind of pore which secrete water and is present on leaf margins. They are commonly found in angiosperms.