|Research Question: How does fertilizer effect the growth of Lemna (Duckweed)?
Hypothesis: If there is more fertilizer in the water, then the Lemna will grow faster, because water normally has minerals of phosphate, nitrate and potassium in limiting supply. If a fertilizer containing phosphates, nitrates and potassium is added to the water then these factors will not be limiting anymore and faster growth will occur.
4 cups or Petri dishes
100ml of each solution below:
½ concentration fertilizer (8 drops/100mL)
¼ concentration fertilizer (4 drops/100mL)
1/8 concentration fertilizer (2 drops/100mL)
1/16 concentration fertilizer (1 drops/100mL)
In pairs set up the following containers.
Each solution should have 2 cups with 100ml of fluid in it. Label carefully.
Make a mark on the outside of the cup of the fluid level. This level must always be kept – so if evaporation occurs it will not have such an impact on your results.
Add 10 leaves of duckweed (Lemna) to each container. Ideally add 10 individual leaves.
Each week record in a table the number of leaves (fronds) in each container.
You will be collecting data for 3-4 weeks.
Collect and record a sheet of class data and to use as additional trials for this experiment.
Draw up a neat table of your data.
Process and manipulate your data.
Graph your processed data.
Using the hypothesis at the beginning of the sheet make a conclusion and evaluate the experiment and give errors and ideas for improvement.
Experimental Problem #2 (Original Problem)
These experiments should be original. Some possible ideas:
*Design an experiment that could be used to compare the effects of nutrient enrichment on two different bodies of water
*Design an experiment to determine what types of household items might be contributing to cultural eutrophication (i.e.: many detergents contain phosphorus, lawn fertilizer contains nitrogen).
*Design an experiment to determine whether or not there is a marked difference in the biological consequences of continuous low-level nutrient enhancement and sudden high-level nutrient enhancement.
Independent Variable: What are you adding/changing in your experiment?_________________________
Dependent Variable: What are your measuring? How do you know eutrophication is occurring?________________
Controls: What aspects are you keeping the same in each group? _________________________