Transpiration And Stomata Flashcards
What four main things affects the transpiration rate
Light intensity
Temperature
Air flow
Humidity
Light intensity ?
The brighter the light the greater the transpiration rate
When does the stomata begin to close (light wise)
As it gets darker
Why does the stomata close when it gets dark
Because photosynthesis can’t happen in the dark so they do t need to be open to let carbon dioxide in
What happens when the stomata is closed
Very little water escapes
Temperature ? (Transpiration raté)
And why
The warmer it gets the faster the transpiration happens
Because when it’s warm water particles have more energy to evaporate and diffuse out of the stomata
Air flow (transpiration rate)
The better the air flow around the leaf the greater the transpiration rate
Why is the transpiration rate better with better air flow
Because there is a higher concentration of water In the air outside the leaf . Diffusion then happens quickly
If air flow is poor around the leaf what happens
The water vapour just surrounds the leaf and doesn’t go away
Humidity (transpiration rate)
The drier the air around the leaf the faster the transpiration rate
What happens if the air is more humid
Theres already a lot of water inside the plant already so isn’t much of a difference between the inside and outside of the leaf
When does diffusion happen fastest (humidity)
If there’s a really high concentration in one place and a really low concentration in the other
How can you estimate the rate of transpiration
Measuring the uptake of water
What are guard cells adapted to do
Open and close the stomata and gas exchange and controlling water loses within the leaf
What happens when the plant has lots of water
Thé guard cell fill with it and go plump and turgid making the stomata open so gases can be exchanged for photosynthesis
