Photosynthesis is performed by green plants using carbon dioxide and water in the presence of sunlight to produce sugar and oxygen. The quality (wavelength) of light can have an influence on the rate of photosynthesis.

1. 080 EFFECT OF WAVELENGTHS OF LIGHT ON
PHOTOSYNTHESIS
Photosynthesis is performed by green plants using carbon dioxide and water in
the presence of sunlight to produce sugar and oxygen. The quality
(wavelength) of light can have an influence on the rate of photosynthesis.
MATERIALS REQUIRED
Beaker, Funnel, Test tube, Water, Razor blade, cellotape (masking tape), Table
lamp, Coloured (red, yellow, green & Blue) cellophane paper (glass paper)
Any small submerged aquatic plant preferably Hydrilla.
Funnel
Test tube Hydrilla water
Table lamp
Razor Blade
cellotape

2. Air bubbles
Hydrilla
Transparent cellophane sheets as colour filters
Blue green yellow red
colourless
as control

3. Fill two-third of a beaker with water. Place the Hydrilla in the beaker with an
inverted funnel over it and place a test tube in an inverted position so that it
covers the stem of the funnel. Keep the set-up in a closed room near a table
lamp. The quality of light coming from table lamp should vary using different
cellophane transparent papers. Care should be taken that no other source of
light should fall on the set up. Photosynthesis will soon begin and the oxygen
released during the photosynthesis process can be seen in the form of bubbles
rising up in the funnel stem.
Note the time taken for the first bubble to be released as well record the
number of bubbles released under each coloured filter for a period of 20
minutes. Count and record the number of bubbles released per minute in each
case. Discuss the variation observed under each case.