1.6 Exchange Surfaces in Plants Flashcards
What facilitates gas exchange in plants?
The structure of the leaf.
What is the main method of gas exchange in plants?
Stomata.
How do gases move within the plant?
By diffusion.
What gases do plants require for photosynthesis and respiration?
- Carbon dioxide for photosynthesis
- Oxygen for respiration
What additional substances do plants require from their environment?
- Water
- Minerals (nitrates/phosphates)
When does most gas exchange occur in plants?
During the day.
What happens to the rates of respiration and photosynthesis when there is no or little light?
Respiration occurs faster than photosynthesis.
What are the structures that control gas exchange in leaves?
Stomata created by guard cells.
What is the role of guard cells?
To control the diffusion of gases and control water loss.
Where are stomata located on the leaf?
On the underside of the leaf (lower epidermis).
Why are stomata located on the underside of the leaf?
This part of the leaf is cooler than the top.
What is the function of the spongy mesophyll layer?
It has air spaces for movement of gases.
What gas is required by all cells in the leaf?
Carbon dioxide.
What happens to oxygen produced during photosynthesis?
Excess oxygen diffuses out.
What results in a concentration gradient of gases in leaves?
The difference in rates of photosynthesis vs respiration during day/night.
What process allows for the evaporation of water in plants?
Transpiration through stomata.
What causes guard cells to open the stomata?
When they take in water.
What happens to guard cells when there is less water?
They become flaccid and close the stomata.
Fill in the blank: Stomata allow the _______ of water.
[evaporation]
