Question

Guttation is due to
A. Negative root pressure
B. Positive root pressure
C. Transpiration
D. None of the above

Answer 1

Hint: The plant’s survival also depends upon the balance of water and nutrients. The plants take the water and use it in the process of photosynthesis to grow. The plants can balance the amount of water they take by the process of guttation.

Complete answer:
Guttation is the loss of water from the tips of the leaves mainly from the infant plants. This process occurs in the plants that have a vascular system like wheat, barley, grass, etc. since the process of guttation relies on the pressures, therefore it can’t occur in the large plants like trees because the pressure required is too large to force out the water. During the night time, it happens when soil is moist and the root absorbs water. If the water is too much, then root pressure causes the water to squeeze out from the tips of the leaves or blade of the plants. As the water is from the soil, it also carries the minerals, enzymes and other chemicals known as xylem sap.
Root pressure causes positive pressure to be created inside the xylem which causes the guttation to occur.

Hence, the correct answer is option (B).

Additional information:
There are some differences between the transpiration and guttation
-Transpiration occurred during the day time when stomata are open while guttation occurred during the night time when stomata remain close.
-The process of guttation happens early in the morning or at night when it is humid and cold, however, transpiration happens in the day time when it is day heat.
-The water is pushed out in the form of vapour in transpiration. In guttation, water or xylem sap is pushed out.

Note: As stomata present on the upper of the leaves and help in the photosynthesis. Therefore it remains open only during the day time. But during the night the plant also gets rid of the excess water from the plants. During the night time plants push out the water through the hydathodes. Hydathodes are also called water stomata. They are mostly similar to the stomata but they can’t open and close as stomata do. They are like pores. They slowly secret out the water from the plants.