Waterloss In Plants And Insects

Question 1

Name the three methods in which insects move gases in tracheal system.

Answer 1

• by simple diffusion down concentration gradients
• tracheal fluid
• by mass transport through contracting and relaxing abdominal muscles

Question 2

How do insects limit water loss?

Answer 2

• waterproof exoskeleton so water only able to diffuse out spiracles, small surface area which water can diffuse out, spiracles able to close when oxygen requirement is low e.g at rest

Question 3

How do plants limit water loss

Answer 3

• curled leaves, hairs and sunken stomata: traps moisture when water vapour diffuses out of plant, high humidity so water potential if high, prevents more water diffusing out
• thick waxy cuticle : reduces evaporation
• longer network of roots: reaches larger surface area of soil, more water can be absorbed

Question 4

Plants adapted to limit water loss are known as…

Answer 4

Xerophytic