3.3.11 The Adaptations of Xerophytic & Hydrophytic Plants

Question 1

What are xerophytes

Answer 1

Plants adapted to conditions where water is scarce

Question 2

Marim Grass adaptations

Answer 2

• Leaves roll into tube (traps moist air, reducing transpiration rate)
• Thick waxy cuticle (less water lost from evaporation)
• Stomata sunken into pits (moist air trapped)
• Shallow roots (retains water)
• Deep roots (access to water deep in soil)

Question 3

Cacti adaptations

Answer 3

• Spines (reduces SA:V so less water lost, deters predators, spines trap moist air)
• Thick waxy cuticle (less evaporation)
• Stomata in sunken pits (moist air)
• Stomata only opens at night (retains water)
• Succulent
• Shallow roots and deep roots

Question 4

Hydrophytes

Answer 4

• Cell wall so dont worry about excess water uptake
• Little need for water transport mechanisms or adaptations to reduce water loss
• Main challenge is receiving enough CO2 and O2

Adaptations :
- Floating leaves
- Thin waterproof waxy cuticle
- Stomata on upper surface of leaves
- Reduced root system
- Water lilys