6.5 - Gas Exchange in Plants Flashcards
Leaf structure and adaptions for gas exchange How plants limit water loss What xerophytes are and their adaptations to reduce water loss (14 cards)
Why do plants need a large leaf surface area?
Photosynthesis
What is a drawback of a large leaf surface area?
Lots of water loss
How do plants limit water loss? Check
Waxy cuticle
What are xerophytes?
Plants adapted to dry environments
What are key adaptations of xerophytes?
Name 3
- Thick waxy cuticle - This reduces water loss through evaporation.
- Rolling or folding of leaves - This encloses the stomata on the lower surface to reduce air flow and the evaporation of water.
- Hairs on leaves - These trap moist air against the leaf surface to reduce the diffusion gradient of water vapour.
- Sunken stomata in pits - These reduce air flow and the evaporation of water.
- Small, needle-like leaves - These reduce the surface area across which water can be lost.
- Water storage organs - These conserve water for when it is in low supply.
What is the function of the upper epidermis with waxy cuticle?
Reduces water loss
What is the function of air spaces in a leaf?
Allow gas diffusion
What is the function of mesophyll cells?
Photosynthesis and gas exchange
What are stomata?
Pores surrounded by guard cells
What is the function of the lower epidermis?
Contains stomata and guard cells
What is the function of vascular tissue?
Transports water and nutrients
How do air spaces aid gas exchange?
Provide a network for gases
How do mesophyll cells aid gas exchange?
Large surface area for diffusion
How do stomata aid gas exchange?
Open for gas exchange
