Question

science 8
unit 1: scientific inquiry & method
g) do plants grow better in white light?

• independent variable:
• dependent variable:
• controlled variables (3):
• control group:

h) does a certain muscle cream double a persons muscle power when used as a part of a muscle - building workout?

• independent variable:
• dependent variable:
• controlled variables (3):
• control group:

i) do mice that eat food exposed to microwaves become smarter and would be able to run through a maze faster?

• independent variable:
• dependent variable:
• controlled variables (3):
• control group:

Explanation:

Step1: Identify independent variable

The independent variable is the factor that is deliberately changed in an experiment.

Step2: Identify dependent variable

The dependent variable is the factor that is measured and is expected to change due to the independent variable.

Step3: Identify controlled variables

Controlled variables are factors that are kept the same in both the experimental and control groups to ensure a fair test.

Step4: Identify control group

The control group is the group that does not receive the treatment (the independent variable) being tested.

Answer:

g)

• Independent variable: Type of light (white light vs other types of light)
• Dependent variable: Plant growth (could be measured by height, number of leaves, biomass etc.)
• Controlled variables (3): Soil type, amount of water, temperature
• Control Group: Plants exposed to non - white light (e.g., red light, blue light)

h)

• Independent variable: Use of muscle cream (cream vs no - cream)
• Dependent variable: Muscle power (could be measured by strength in lifting weights, force exerted etc.)
• Controlled variables (3): Workout routine, diet, age of the person
• Control Group: People in the muscle - building workout who do not use the muscle cream

i)

• Independent variable: Exposure of food to microwaves (microwaved food vs non - microwaved food)
• Dependent variable: Mice intelligence (measured by time to run through a maze)
• Controlled variables (3): Type of food, breed of mice, age of mice
• Control Group: Mice that eat non - microwaved food