DENDROLOGY

DENDROLOGY AND SOCIETY

MORPHOLOGY AND IDENTIFICATION

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
The two structures that limit transpiration or regulate water loss in the plant are known as
A
Guard cells and xylem
B
Stomata and guard cells
C
xylem and phloem
D
stomata and phloem
Explanation: 

Detailed explanation-1: -Stomata are composed of a pair of specialized epidermal cells referred to as guard cells (Figure 3). Stomata regulate gas exchange between the plant and environment and control of water loss by changing the size of the stomatal pore.

Detailed explanation-2: -What are guard cells? A pair of guard. cells surrounds each stoma on the leaf surface. Stomata are important because they regulate the uptake of CO2 from the atmosphere for photosynthesis and also the loss of water vapour from the plant during transpiration.

Detailed explanation-3: -Thick, waxy cuticle – having leaves covered by a thickened cuticle prevents water loss from the leaf surface. Stomata in pits – having stomata in pits, surrounded by hairs, traps water vapour and hence reduces transpiration.

Detailed explanation-4: -Water loss through transpiration can be reduced by closing the stomata in the leaves using a substance called ABA. When the stomata is closed photosynthesis will decrease because no CO2 can enter through the closed stomata. Less photosynthesis means less energy is produced by the plant and the plant stops growing.

There is 1 question to complete.