Cacti plants have adapted to desert conditions. Image credit

Cacti plants have adapted to desert conditions. Image credit

ZIMSEC O Level Combined Science Notes: Plant adaptations to transpiration

  • Plants that live in extreme weather conditions have adapted as they have lived in these conditions for a long time.
  • In places such as Hot Deserts plants are able to grow and survive despite the extreme heat and lack of water.
  • Many adaptations have to do with leaf structure.
  • The larger the surface area of a leaf the great the amount of water that is lost via transpiration.
  • Leaves of plants that live in arid conditions tend to be small, thin or reduced to spines of thorns such as that those of cacti.
  • Some grasses also curl up their leaves inwards to reduce the surface area exposed to the air and to trap water vapour inside the enclosed space.
  • The number of stomata also affects the rate of transpiration.
  • The less the stomata on a leaf the less water will be lost by the leaf.
  • Most stomata is found on the lower side surface of leaves.
  • This results in less water being lost via transpiration.
  • This reduces transpiration.
  • The surface of these plants might also be protected by a thick, waxy waterproof cuticle and hairs.
  • Some have stomata that are sunk in pits.
  • All this traps moisture and reduces transpiration.
  • Plants that grow in arid (dry) areas usually have an extensive root system so as to maximize water uptake.
  • Some have long tap roots that can reach the deep water tables.
  • Plants like cacti have stems that can store water.

To access more topics go to the Combined Science Notes page.

- See latest Zimbabwe grocery prices -


We publish the latest grocery prices from Zimbabwean supermarkets. We also deliver groceries online