transpiration Flashcards
what is transpiration?
water constantly evaporating from the surface of the leaves
what does transpiration start with?
evaporation of water from the cells inside the leaf
what happens after water is evaporated?
water vapour diffuses through air spaces of the spongy mesophll and out through the leaf of the stomata
what is the last event that takes place?
water passes from xylem into the leaf to replace the water that has been lost
what is the very last event to happen?
water is drawn into the root hair cells and up the xylem vessels to leaf
why does transpiration take place in leaves?
transports water to the leaves for photosynthesis and transports dissolved mineral ions and it cools the leaf down
what is the first factor that affects the rate of transpiration?
greater at higher temperatures- faster evaporation as the temp is higher
what is the second factor that has an affect on the rate of transpiration?
faster under dry conditions - evaporation takes place quicker under dry conditions
what is a third factor that affect the transpiration rate?
transpiration increases in windy conditions- wind removes water vapour allowing more water to evaporate
What is the final factor that has an affect on the rate of transpiration?
rate of transpiration increases when the light intensity increases - high light intensity increases photosynthesis
what is the final final step of transpiration?
stomata open to allow carbon dioxide to enter, water vapour passes out leaf
how do guard cells work?
light intesity high guard cells swell up and change shape - stomata opens - carbon dioxide can diffuse into leaf
what does the stomata do under hot conditions?
it closes to reduce water loss - cannot photosynthesise
What does the xylem transport?
water and dissolved mineral ions
What does the phloem transport?
dissolved sugars
