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Adaptations Xerophytes (desert plants):
Structural adaptations:
The number of the stomata
is reduced so that few or no pores at exposed to water loss through
transpiration
Their leaves are modified
into spines/ thorn like structures to reduce the area exposed for
transpiration
The leaves have a thick
waxy cuticle to reduce water through the cuticular transpiration.
They have deep roots that
extend to the water tables beneath the soil for their survival.
Most of them have
superficial roots that form large extensions on the surface the earth to
make use of the torrential rain that happen sporadically.
Some have hairy leaves
that trap water vapour in between them to lower the diffusion gradient
hence reducing water loss.
Physiological
adaptations:
They fold their leaves
especially during the day to decrease the number of the stomata that is
exposed hence reducing the rate of transpiration
They shed their leaves
during dry seasons son that they would avoid water loss through
transpiration
Some experience reversed
stomatal rhythm. That is the stomata opens at night when the rate of
transpiration is low for gaseous exchange but closes during the day when
the rate of transpiration is high
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