Question

Please help this is due 9 hours

Scientists often use controlled experiments to answer questions.
Choose the three correct statements about controlled experiments.
A) No changes are made to a test group in an experiment.
B) A control group is used for comparison to other groups.
C) Only one change can be made per test group in an experiment.
D) Changes can only be made to the control group in an experiment.
E) A controlled experiment must have a control group and test group(s).

Answer 1

Answer: B, C, E

Explanation B is correct due to the fact the control groups are design to compare the results from the experiments to the control group which is ensures that the experiments actually work

Explanation: C is correct because each experiment group can only have one change made to it that differs from the control group. If you made multiple changes to one group you would not know what change you made that resulting in how your experiment ended up

Explanation E: An experiment is not scientifically proven unless you have a control group hence the need for both test groups and a control group

Answer 2

B) A control group is used for comparison to other groups.

E) A controlled experiment must have a control group and test group(s).

C) Only one change can be made per test group in an experiment.