Sam’s Experiment’s Independent Variable: Fertilizer run-off and Algae growth
Sam created an experiment using five 1000mL glass beakers. Each contained 900mL water, 5mL water from an aquarium containing high levels of algae. The beakers were then diluted with different amounts of fertilizer: Beaker A-8 ml; Beaker B-6 ml; Beaker C-4 ml; Beaker F- 4 ml; Beaker H- 2 ml and Beaker W- 1 ml. To count the amount of algae cells, each week, each beaker was placed under a light source for twelve hours. Each beaker was then examined with a microscope. This experiment has an independent variable, which is the amount of fertilizer that was applied to each beaker. Sam will be manipulating this variable in order to study the impact of fertilizer runoff on the growth and development of alga. Sam is testing various amounts of fertilizer to see how they affect the growth of the algae in each beaker. Sam is able to determine the effect of fertilizer runoff on the growth of alga cells by comparing their numbers in the beakers. Cont….