IGCSE marine practical 4.3 Photosynthesis

 In IGCSE Marine science we have looked at the practial experiment with Photosynthesis.

What we used:

Sodium Hydrocarbon solution

Boiling tube

paper clip

Scissors

Elodea canadensis plants

A strong lamp (for an aquarium)

A ruler

A clock for meassuring time

How we did it:

We cut the Elodea canadensis so there is intact end and a cut end

Put a paper clip on the intact end and put it in the boiling tube with water and the sodium hydrocarbon solution

Set up the boiling tube and the lamp, so there is a 5 cm distance.

Turn on the light and count the number of bubbles for a set time.

Repeat again with an increasing distance.

We did not use the water bath as in the book. If you do that, you will get a better experiment as you control the variables better (temperature)

Results:

Both groups saw a clear decline in the amount of bubbles as we increased the distance of the light to the boiling tube.

This represents a lower rate photosynthesis as the light intensity is lowered.

Here is another way of setting up an experiment with light and oxygen production