Final answer:
Controls in cell biology experiments are used to establish a baseline for comparison and ensure that any observed effects are due to the manipulated variable. They can include placebos or normal/untreated groups that serve as reference points for comparison.
Step-by-step explanation:
In cell biology experiments, controls are used to provide a baseline for comparison and to ensure that any observed effects are due to the manipulated variable. A control is a part of the experiment that does not change. One example of a control in cell biology experiments is the use of a placebo or a substance that is known not to have any effect. For instance, in an experiment testing the effects of a new drug on cell growth, the control group would receive a placebo instead of the drug.
Another example of a control in cell biology experiments is the use of a normal or untreated group. This group receives no experimental treatment and serves as a reference point. It allows researchers to compare the effects of the manipulated variable to the normal conditions. For example, in an experiment studying the effect of a nutrient on cell division, a control group of cells would be grown in a nutrient-rich medium, while the experimental group would be grown in a nutrient-depleted medium. By comparing the growth rates of the two groups, researchers can determine the effect of the nutrient on cell division.
In summary, controls in cell biology experiments are used to establish a baseline for comparison and ensure that any observed effects are due to the manipulated variable. They can include placebos or normal/untreated groups that serve as reference points for comparison.