Multicellular organisms require transport systems to supply their cells and remove waste products. Plants transport substances through xylem and phloem.
The loss of water from the leaves of a plant is called transpirationThe loss of water from leaves by evaporation through the stomata., and the resulting flow of water through the plant is called the transpiration stream. The transpiration stream is important because:
It carries water for photosynthesis to the mesophyll cells: the upper layer of cells where photosynthesis mostly takes place in the leaves.
The water carries essential mineral salts dissolved in solution.
The rate of transpiration is affected by wind speed, humidity, temperature and surface area.
You can investigate the rate of transpiration using a potometer. Watch the video below to see the correct procedure for doing this.
