Xerophytes 0.0 / 5 ? BiologyCellular processes and structureASOCR Created by: Steff06Created on: 01-05-16 15:00 What is a xerophyte? A plant that is adapted to reduce water loss so that it can survive in very dry conditions. 1 of 18 Why is the loss of water by transpiration unavoidable? Stomata are open during the day for gaseous exchange and photosynthesis. Water will lost through these stomata. 2 of 18 What adaptations do most plants have to reduce water loss? Waxy cuticle, stomata on under surface, stomata closed at night, deciduous plants lose leaves in winter. 3 of 18 How does a waxy cuticle reduce water loss? Waxy cuticle on the leaf to reduce water loss due to evaporation through epidermis. 4 of 18 How do stomata on the under surface reduce water loss? Not directly heated from sun - reduces evaporation and water loss. 5 of 18 How does stomata being closed at night affect water loss? No light available for photosynthesis so close to reduce water loss. 6 of 18 How do deciduous plants reduce water loss? Lose leaves in winter so no water lost from leaves. 7 of 18 What are adaptations of xerophytes? Smaller leaves, stomata close when water availability is low, thicker waxy cuticle, spongy mesophyll, pits, hairs, high salt con, rolling leaves. 8 of 18 How do smaller leaves reduce water loss? Reduce SA, so less water is lost by transpiration. 9 of 18 What does a thicker waxy cuticle do? Reduces evaporation. 10 of 18 What is the effect of stomata closing when availability of water is low? Reduces water loss though stomata. 11 of 18 What does densely packed spongy mesophyll do? Reduces SA exposed to air, less water will evaporate. 12 of 18 What is the effect of having pits at the base of stomata? Trap air saturated with water vapour, reduces potential gradient. 13 of 18 What do the hairs on the surface do? Trap air which will become saturated with moisture and reduce diffusion of water vapour as potential gradient is reduced. 14 of 18 How does rolling leaves reduce loss of water vapour? Lower epidermis not exposed to atmosphere and will trap saturated air, reducing gradient. 15 of 18 What does a high conc of salt in cells mean? Lowers water potential. Less evaporation. 16 of 18 Where is Marram grass adapted to live? On sand dunes. 17 of 18 What adaptations does Marram grass have? Leaf rolled up, thick waxy cuticle, trapped air, hairs on surface, stomata in pits. 18 of 18
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