Gas Exchange in The Leaf of a Plan

?
  • Created by: Molly
  • Created on: 24-04-13 15:19
What happens when plants photosynthesise?
Plant cells take in CO2 and produce O2.
1 of 12
How are the diffusion gradients in and out of the lead maintained?
By mitochondria carrying out respiration and chloroplasts carrying out photosynthesis.
2 of 12
When photosynthesis is taking place, where does the carbon dioxide come from?
Some can come from the respiration of cells but most of it has to be obtained from the external air
3 of 12
Why does oxygen diffuse in to the lead when photosynthesis is NOT occuring (e.g. it is dark)?
Because it is constantly being used by cells during respiration. In the same way, carbon dioxide produced during respiration diffuses out.
4 of 12
How is gas exchange in plants similar to gas exchange in insects?
No living cell is far away from the externail air, and therefore a source of oxygen and carbon dioxide. Diffusion takes place in the gas phase (air), which makes it more rapid than if it were in water.
5 of 12
Why isn't a specialised transport system needed for gases to diffuse in and out of leaves?
Because a plant leaf has a very large suface area compared to volume of living tissue ratio.
6 of 12
How are leaves adapted for rapid diffusion?
They have a thin, flat shape that provides a large surface area. Thy have many pores called stomata in the lower epidermis. They have numerous connecting air spaces that occur throughout the mesophyll.
7 of 12
What are stomata?
Minute pores which occur mainly in leaves.
8 of 12
What cells surround the stomata?
Guard Cells
9 of 12
What do the guard cells do/ What are they in charge of
The guard cells can open and close the stomatal pore and therefore control the rate of gaseous exchange.
10 of 12
State two differences between gas exchange in a plant leaf and gas exchange in a terrestrial insect?
Insects may create mass air flow by ventilation, plants do not do this. Insects have smaller surface area to volume ratio than plants.
11 of 12
What is the advantage to a plant being able to control the opening and the closing of the stomata?
Helps to control water loss by evaporation/transpiration.
12 of 12

Other cards in this set

Card 2

Front

How are the diffusion gradients in and out of the lead maintained?

Back

By mitochondria carrying out respiration and chloroplasts carrying out photosynthesis.

Card 3

Front

When photosynthesis is taking place, where does the carbon dioxide come from?

Back

Preview of the front of card 3

Card 4

Front

Why does oxygen diffuse in to the lead when photosynthesis is NOT occuring (e.g. it is dark)?

Back

Preview of the front of card 4

Card 5

Front

How is gas exchange in plants similar to gas exchange in insects?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Biological molecules, organic chemistry and biochemistry resources »