22. Analyzing Experimental Data on Photosynthesis Rates

This session works through a sample experiment measuring photosynthesis rate, such as counting oxygen bubbles released by aquatic plants under different light intensities, and uses it to review the structure of a scientific experiment.

Every well-designed experiment has an independent variable (the factor the experimenter deliberately changes — here, light intensity), a dependent variable (the factor being measured in response — here, bubble count or oxygen release rate), and controlled variables (everything else held constant, such as water temperature and plant species, so that any change in the result can be attributed to the independent variable alone).

Given a data table from an experiment like this, the goal is to move from raw numbers to a written, evidence-based conclusion: does the data show a clear trend, and does that trend match what the biology from Unit 2 predicts? Practice includes identifying the variables in a described experiment, reading a results table, and writing a short conclusion statement that a data table actually supports — a core GED® Science skill.