Describe how environmental factors increase the rate of transpiration in terrestrial plants.

K.C.S.E Biology Q & A - MODEL 2012PP2QN08

Describe how environmental factors increase the rate of transpiration in terrestrial plants.

ANSWERS

In bright light; stomata are fully/wide open; increasing contact between the atmosphere and air spaces in the leaf; This in turn increases water loss by evaporation through the
open stomata
High environmental temperatures; increase the rate of evaporation from the leaf surface
thus more water leaves cells due to the increased diffusion gradient;
Iii a windy day; air around the leaf is carried away reducing water vapour around the
leaf; more water moves into the atmosphere from the leaf air spaces;
In low humidity/when the atmosphere is less saturated with water vapour; more
water will move from leaf air spaces into the atmosphere; leading to increased rate of
transpiration; .
Low atmosphere pressure; increases diffusion gradient between atmospheric and leaf
increased rate of evaporation;Availability of water; causes turgidity of guard cells hence stomata open; increasing
rate of transpiration.