Gas Exchange In The Leaf Of A Plant Flashcards
When photosynthesis is taking place although some co2 comes from respiration of Cells, most of it is obtained from where? How’s this similar to oxygen diffusing out of the plant
The external air.
Some oxygen from photosynthesis is used in respiration but most of it diffuses out of the plant
What is still happening when photosynthesis is not occurring
Oxygen diffuse into the leaf because it is constantly being used by cells during respiration
In the same way, co2 produced during respiration diffuses out
How is gas exchange in plants similar to that of insects
No living cell is far from the external air, and therefore a source of oxygen and carbon dioxide
Diffusion takes place in the gas phase, which makes it more rapid then if it were in water
How is the plant adapted for rapid diffusion
Many small pores, called stomata, and so no cell is far from a stone and therefore the diffusion pathway is short
Numerous interconnecting air spaces that occur throughout the mesophyll so that gases can readily come in contact with mesophyll cells
Large surface area of mesophyll cells for rapid diffusion
What helps stomata open and close. What does this mean
Guard cells
They control the rate of gaseous exchange
How do plants prevent water loss
By closing the stomata at times when water loss would be excessive
