Xerophytes
- Created by: Steff06
- Created on: 01-05-16 14:12
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- Xerophytes
- Unaviodable loss:
- Loss of water by transpiration is unavoidable.
- Stomata are open during the day and water will be lost when gases are exchanged.
- Xerophyte is a plant that is adapted to reduce water loss so that it can survive in very dry conditions.
- Adaptations of most plants:
- Waxy cuticle - Reduces water loss due to evaporation through the epidermis.
- Stomata on under surface - Reduces evaporation due to non direct heating from sun.
- Stomata are closed at night when there is no light for photosynthesis.
- Deciduous plants lose leaves in winter.
- Adaptations of xerophytes:
- Smaller leaves - Reduces SA so less water is lost by transpiration.
- Densely packed spongy mesophyll - Reduces SA exposed to air, less water will evaporate.
- Thicker waxy cuticle - Reduces evaporation.
- Closing stomata when water availability is low - Reduces water loss.
- Hairs on surface - Trap air which will become saturated with moisture and reduce diffusion of water vapour as potential gradient has been reduced.
- Pits containing stomata at base - Trap saturated water vapour air, reduced gradient.
- Rolling leaves - Lower epidermis not exposed to atmosphere can trap saturated air. Reduce gradient.
- High salt conc in cells - low water potential. Less evaporation.
- Unaviodable loss:
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