Question

A student decides to test the affects of acidity on plant growth. How should they carry out the experiment?

Get 10 plants that are as similar as possible, and expose them all to different amounts of acidity, sun and water so that you know the effect of these other variables in addition to acidity.

Get 10 totally different plants so that they can see how acidity affects different kinds of plants.

Get 10 plants that are as similar as possible, and ensure that they are exposed to the same amount of sun and water, varying only the amount of acidity they're exposed to.

Get only