Plant adaptations Flashcards
What are the 2 types of plant?
Xerophyte and hydrophyte
What is a xerophyte?
A plant that is adapted to reduce water loss so it can survive in very dry conditions
What are examples of xerophytes?
Conifers, marram grass and cacti
What are adaptations of xerophytes?
Stomata in sunken pits, hairs, thick waxy cuticle, rolled leaves, fewer stomata, water storage, less leaves, root adaptations and avoidance
What is the function of stomata in sunken pits?
Air is not moved away by air currents but becomes trapped around the stomata and water molecules saturated the air to create local humidity?
What is the effect of stomata sunken in pits?
It reduces the water vapour diffusion gradient
What is the effect of hairs?
They create local humidity next to leaf and decrease exposure to air currents by reducing air flow around stomata
What is the function of the thick waxy cuticle?
Leaf is more impermeable to water and less water is lost from leaf surface
What is the function of rolled leaves?
Stomata on inside of a rolled leaf to decrease exposure to air currents and air becomes trapped around stomata as water vapour molecules evaporate into a humid space
What is the effect of rolled leaves?
It reduces the water diffusion gradient
What is the function of fewer stomata?
It decreases transpiration as this is were water is lost
What is the function of water storage?
To store water for times of drought in specialised parenchyma tissue in roots and stems in succulents
What is the function of leaf loss?
Prevent water loss by losing their leaves in times of drought such as desert tree which trunk and leaves turn green to photosynthesis with minimum water loss
What is the function of root adaptations?
Long tap roots can penetrate several metres as widespread shallow roots provide large SA for absorbing as much water as possible
What is the function of avoidance?
Plants can lose their leaves, become dormant, die leaving their seeds behind or survive on storage organs so some can withstand complete dehydration and recover when rain arrives