6.5 limiting water loss

Question 1

plants adaptations to minimise water loss

Answer 1

• thick cuticle => increases diffusion distance
• waxy cuticle => reduces transpiration.
• rolling up of leaves => ‘trap’ water vapour and water potential gradient decreased;
• stomata in pits or grooves= > ‘trap’ water vapour and water potential gradient decreased;
• hairy leaves=> ‘trap’ water vapour and water potential gradient decreased;
• Spines/needles => reduces SA: V ratio

Question 2

insects adaptations to minimise water loss

Answer 2

• small surface area to volume ratio-> minimise the area over which water is lost
• waterproof coverings-> water cannot escape
• spiracles -> can be closed