Learning ObjectivesYou should be able to:
(a) identify the positions and explain the functions of xylem vessels, phloem (sieve tube elements and companion cells) in sections of a herbaceous dicotyledonous leaf and stem, under the light microscope (b) relate the structure and functions of root hairs to their surface area, and to water and ion uptake (c) explain the movement of water between plant cells, and between them and the environment in terms of water potential. (Calculations on water potential are not required) (d) outline the pathway by which water is transported from the roots to the leaves through the xylem vessels (e) define the term transpiration and explain that transpiration is a consequence of gaseous exchange in plants (f) describe and explain • the effects of variation of air movement, temperature, humidity and light intensity on transpiration rate • how wilting occurs (g) define the term translocation as the transport of food in the phloem tissue and illustrate the process through translocation studies |
Brain Squeeze!
How do plants transport water from the roots to the leaves over such distances? Do they have a heart like humans to pump fluid around the plant and to the leaves?
What problems do plants face? Lets watch the video below to find out more! |