The student clearly states the independent variable as different lactase concentrations and the dependent variable as the breakdown of lactose, measured by absorbance. The research question includes a method of analysis that effectively outlines how absorbance at 540 nm will be used to determine the effect of lactase concentrations. The student provides a comprehensive background theory relevant to the investigation, detailing enzyme functions and personal motivations. Controlled variables are well-defined, and safety, ethical, and environmental issues are appropriately addressed. However, the student does not adequately explain the choice of sampling technique or justify the number of trials, which are areas for improvement. Overall, the methodology is detailed and reproducible, with no irrelevant information present.
