Transpiration and Factors Affecting its Rate Flashcards
Palisade mesophyll
Where photosynthesis takes place
Xylem tissue
Transports water and minerals from roots to leaves
Root hair cells
Water enters the plant here
What process is happened when water is constantly evaporating from the surfaces of the leaves?
Transpiration
How does transpiration work?
Starts with the evaporation of cells from inside the leaf. Water vapour diffuses in the air spaces of spongy mesophyll and out the leaf through stomata. Water passes through the xylem into the leaf to replace the water lost. Water is drawn into the root hair cells and up the xylem vessels to the leaf
What does transpiration do?
Brings water to the leaf, required for photosynthesis
What does transpiration steam do?
Transports dissolve mineral ions, like magnesium which are used to make chlorophyll
Why is evaporation in the leaf important?
It keeps the leaf cool, especially in warm weather
The rate of transpiration is greater at…
Higher temperatures, because this is when evaporation is faster
Transpiration is also faster at…
Dry conditions because the air is not humid and evaporation is quicker
The rate of transpiration increases in…
Windy conditions because wind removes water vapour, allowing any more water to evaporate
The rate of transpiration increases when…
Light intensity increases because high light intensity increases the rate of photosynthesis and when the stomata opens, water vapour can pass out of the leaf and evaporate
Stomata are surrounded by two guard cells, and…
When the light intensity is high (day), the guard cells swell and change shape, which causes stomata to open, allowing CO2 to diffuse into the leaf and be used in photosynthesis
Under hot conditions, the plant closes its stomata to…
Reduce water loss by transpiration, which means that the plant can’t photosynthesise
