Page 223 - Primary Six Notes
P. 223
Experiment to show that plants lose water.
Get a transparent polythene paper without a hole on it
Look for a plant which is well placed in the sunlight
Tie the polythene paper on one of the branches or around the
shoot as shown below
Leave it there for about 2 hours
Observation
Droplets of water are found on the inside of the polythene bag
Conclusion
Plants give off water in form of water vapour
Factors which determine the rate of transpiration
Temperature. Plants lose a lot f water on a hot day than a
cool day
Light. Light increases the rate of water loss, i.e. the stoma-
ta are open during day and closed at night
Wind. When it is windy, the rate of transpiration is very high
because more vapour is blown away from the leaf surfaces.
