What is the independent variable in this experiment?
A) Number of algal cells
B) Amount of fertilizer
C) Hours of daylight
D) Amount of water

What is the dependent variable in this experiment?
A) Number of algal cells
B) Amount of fertilizer
C) Size of the beakers
D) Hours of daylight

Which of the following is not a controlled variable in this experiment?
A) Amount of aquarium water
B) Amount of fertilizer
C) Size of the beaker
D) Amount of light

Which of the following is the control group for this experiment?
A) Beakers A & B
B) Beakers B & C
C) Beaker D
D) Beaker E​