Which term refers to a set of statements explaining a group of facts or phenomena, especially after repeated testing?

• A. Law
• B. Theory
• C. Metabolism
• D. Endosymbiotic theory

Answer: (B)

A theory is a well-supported set of statements that explain a group of facts or phenomena, especially after repeated testing. It ties together many observations and experimental results to explain why things happen and to predict new outcomes that can be tested again. The strength of a theory lies in its consistency across diverse evidence and its ability to make testable predictions. Over time, as more data accumulate and experiments are repeated, a theory becomes more reliable.

By comparison, a law describes a consistent pattern or rule in nature—what happens under certain conditions—without necessarily explaining why it happens. Metabolism is the set of chemical reactions that sustain life inside organisms, not a broad explanatory framework. Endosymbiotic theory is a specific example of a theory about how certain cellular structures originated, not the general concept itself.