Dependent and Independent Variables

An experiment is being done to determine how light affects the growth of small zinnia plants. One plant is placed in full sunlight, the second in a shaded area, the third in an unlit closet. What is the independent variable in the experiment?

• the amount of light
• the type of plants
• the type of soil
• the length of the experiment

An experiment is being done to determine how light affects the growth of small zinnia plants. One plant is placed in full sunlight, the second in a shaded area, the third in an unlit closet. The hypothesis of this experiment could be:

• Plants grow differently under different conditions.
• Zinnia plants in direct sunlight grow taller than zinnia plants in little or no sunlight.
• Many things, including sunlight, affect the growth of a plant.

True or False - Experiments should have many independent variables.

• TRUE
• FALSE

True or False - In order to avoid confusing or conflicting results, an experiment should not be repeated.

• TRUE
• FALSE

An experiment is being done to determine how light affects the growth of small zinnia plants. One plant is placed in full sunlight, the second in a shaded area, the third in an unlit closet. What is the independent variable in the zinnia experiment?

• The plant growth
• The amount of sunlight
• The length of time needed to conduct the experiment
• The amount of water given daily

What is it called when a scientist repeats an experiment several times in the exact same way?

• Hypothesis testing
• Repeated trials
• Sloppy work

What observations might you make about a nearby cat?

• The cat is black and white.
• The cat is hungry.
• The cat is lost.

What can you infer about the cat you observed eating?

• The cat is black and white.
• The cat is fat.
• The cat is hungry.
• The cat is eating.

This variable in an experiment is the one being deliberately changed by the scientist. 

• dependent variable
• independent variable
• data
• control group

In a controlled experiment, how many variables can be worked with at a time? 

• one
• none
• two or more
• how ever many makes sense.