Question

why do we need to have experimental controls?
a) ensure the biological variability will not influence the results
b) reduce variability in the results
c) make the experiment reproducible
d) ensure that changes in the dependent variable depend on the independent variable

Explanation:

Experimental controls are designed to isolate the effect of the independent variable. By keeping all other factors constant, they ensure that any observed changes in the dependent variable can only be attributed to the independent variable, rather than confounding factors. While controls can reduce variability and aid reproducibility, their core purpose is establishing this causal link. Option a is incorrect because controls manage, not eliminate, biological variability. Option b is a secondary benefit, not the primary reason. Option c is also a secondary outcome, not the core purpose.

Answer:

d) Ensure that changes in the dependent variable depend on the independent variable