Question

Why is a control group important in a scientific experiment?

It provides a comparison to the test group.
It gives the scientist control over which variables to change.
It is the group experiencing the changing variables.
It gives the scientist control over when to change variables.

Answer 1

A- it provides a comparison to the test group. hope that helps :)

Answer 2

A control group is a group separated from the rest of the experiment such that the independent variable being tested cannot influence the results. This isolates the independent variable's effects on the experiment and can help rule out alternative explanations of the experimental results