Pleurococcus is a green, single-celled algae that is found on the bark
of trees, where it survives better on the north side of the tree and
near the ground. It can also be found on stones and fences and usually
in moist situations. As it is a green plant, as all green plants do -
The chemical reaction that is taking place is:
Carbon Dioxide + Water Glucose + Oxygen
[IMAGE]6CO2 + 6H2O C6H1206 + 6O2
Variables that affect Pleurococcus:
Ø Light: is required for photosynthesis
Ø Moisture/humidity: if it is ...view middle of the document...
My hypothesis is that the side of the tree with the least light will
have the most Pleurococcus, as too much light will make the
Pleurococcus dry out and die, as it has no roots, and the only
technique that it can obtain water, is the water that trickles down
the tree through rainfall. It requires rainfall for photosynthesis, as
the equation for Photosynthesis is
Carbon Dioxide + Water Glucose + Oxygen.
So, the most Pleurococcus will grow on the north side because the
least light is exposed to the north side of the tree, as the sun rises
in the east and sets in the west, exposing the south side to the most
light, leaving the north side with the least light. Therefore, the
least amount of Pleurococcus will grow on the south side, as it is
exposed to the most sunlight.
Ø Quadrat (10 x 10 squares; altogether 100 squares)
Ø Metre ruler
Ø Light sensor
1. Collect the apparatus above.
2. Use the compass to find out which way is North.
3. Use the metre ruler to find out how high one metre on the tree is.
4. Use the light sensor to find out how much light there is on the
north side at one metre high and record the result.
5. At one metre on the north side, place the quadrat on the tree and
count how many squares contain Pleurococcus, and record the result.
6. Do the same for the east, south and west side.
7. Do 1-6 for another 9 trees, leaving you with the results of ten
To make it a fair test, I am going to make sure that I always use the
same type of tree, and make sure that the equipment we use is always
the same. To test if the equipment works, we will make sure that we
test it first. We will also make sure that we always measure the
Pleurococcus and the Light from exactly one metre high. Also, we will
make sure that the same person is measuring one metre, the same person
is measuring the light, and the same person is counting the amount of
Pleurococcus. We will also make sure that the range of trees we pick
will always be the same. We will repeat this experiment on ten trees
to make sure that the results we obtain are accurate and make it a
fair test. We will also make sure that we use the same type of quadrat
each time - 10 x 10 squares (100 squares altogether which will give us
a percentage). This is only a sample of how much Pleurococcus there
actually is on a tree.
Amount of Algae (%)
Amount of light (%)