CH9 plant adaptations to water availability

Question 1

Xerophytes

Answer 1

• plants in dry habitats
• evolved wide range of adaptations to live and reproduce in places with little water

Question 2

Xerophyte ways of conserving water

Answer 2

• thick waxy cuticle
• sunken stomata, reduces air movement
• reduced numbers of stomata and leaves
• hairy leaves and curled leaves, creates microclimate of still, humid air
• succulents, store water in specialised tissue
• leaf loss / avoiding the problems
• root adaptations

Question 3

Hydrophytes

Answer 3

• plants that live in water
• important leaves float so they are near surface for photosynthesis

Question 4

Adaptations of hydrophytes

Answer 4

• very thin or no waxy cuticle and many open stomata
• reduced structure to plants, water supports leaves
• wide, flat leaves
• small roots/ large surface area of stems and roots underwater
• air sacs
• aerenchyma

Question 5

What are aerenchyma

Answer 5

• specialised parenchyma tissue
• has many large air spaces, makes leaves and stems more buoyant
• forms a low resistance internal pathway for movement of water