Practical Work
- Investigation of the transpiration in potted plant
Problem:Explain the occurrence of transpiration.
Apparatus required:A potted plant, 2 bell -jars, polythene bag, copper sulphate.
Background information: 1.transpiration is the loss of water from plant surface.
2.Polythene bag stops the escape of water vapours.
Hypothesis: Transpiration occurs in plant which are given adequate supply of water and are placed in light.
Procedure: 1. Take a potted in plant and cover the pot and base of stem with polythene bag.
- Place the potted plant on a glass plate and invert a dry ball-jar over the pot and plant.
- Leave the apparatus in sunlight.
- Set up a control experiment with no plant.
Observation: After an hour drops of colourless liquid are seen inside the bell-jar with the plant. To show that these drops are water touch them with anhydrous copper sulphate (white) and its colour changes to blue. No drops of water are found in the control experiment where there was no plant.
Results:The water droplets on the inside of the jar containing the plant came from the leaves because the rest of the plant body and the soil were covered with polythene bag. Thus the potted plant present in the bell-jar showed the phenomenon of transpiration.
Experiment set up for transpiration in potted plant.
Source of Photo
All data collected from my book of Science.
