Revision on xerophytes and hydrophtes

04.02.2020
08:49:18
Biology/Grade 10- Today’s topic for revision-Xerophytes and hydrophytes- course book -pages 251 to 253
Main points-

Adaptations to arid conditions:
In both hot and cold climates plants may suffer from water shortage.
High temperatures accelerate evaporation from leaves.
At very low temperatures the soil water becomes frozen and therefore unavailable to the roots of plants.
Plants modified to cope with lack of water are called xerophytes.
Loss of leaves removes virtually all evaporating surfaces at a time when water may become unavailable.
Pine tree and Cacti .


Adaptations to living in water:
Plants adapted to living in water are called hydrophytes.

Water lily.
The leaves contain large air spaces to make them buoyant, so they float on or near the surface.
This enables them to gain light for photosynthesis.
The lower epidermis lacks stomata to prevent water entering the air spaces, while stomata are present on the upper epidermis for gas exchange.



Homework worksheet is given on xerophytes