EVERYDAY SCIENCE

Detailed explanation-1: -Water is used as one of the agents as a control for the lab because it does not limit the bacterial growth. The water should have no effect of the bacterial growth and should have a zone of inhibition of zero.

Detailed explanation-2: -However, a lot of gene regulation occurs at the level of transcription. Bacteria have specific regulatory molecules that control whether a particular gene will be transcribed into mRNA. Often, these molecules act by binding to DNA near the gene and helping or blocking the transcription enzyme, RNA polymerase.

Detailed explanation-3: -Controls allow the experimenter to minimize the effects of factors other than the one being tested. It’s how we know an experiment is testing the thing it claims to be testing. This goes beyond science-controls are necessary for any sort of experimental testing, no matter the subject area.

Detailed explanation-4: -A good example would be an experiment to test drug effects. The sample receiving the drug would be the experimental group while the sample receiving a placebo would be the control group. While all variables are kept similar (e.g. age, sex, etc.) the only difference between the groups is the taking of medication.