What is the general purpose of controls in experiments?

What is the general purpose of controls in experiments?

• A. To measure baseline DNA concentration
• B. To complicate data
• C. To validate that results are due to the experimental variable and not external factors
• D. To increase cost

Answer: (C)

Controls ensure that observed changes come from the factor you’re testing, not from other variables. By keeping all other conditions the same and only changing the experimental variable, you create a baseline for comparison and can attribute any differences to the variable of interest. They also help reveal problems like unintended influences or measurement errors. Negative controls show no effect when the variable isn’t applied, while positive controls confirm the system can produce a response, making it clear that a lack of effect in the test isn’t due to a faulty setup. This is why controls are used to validate that results arise from the experimental variable and not external factors.

Controls ensure that observed changes come from the factor you’re testing, not from other variables. By keeping all other conditions the same and only changing the experimental variable, you create a baseline for comparison and can attribute any differences to the variable of interest. They also help reveal problems like unintended influences or measurement errors. Negative controls show no effect when the variable isn’t applied, while positive controls confirm the system can produce a response, making it clear that a lack of effect in the test isn’t due to a faulty setup. This is why controls are used to validate that results arise from the experimental variable and not external factors.