Scientific Investigation, Experimental Design and Biological Data
This lesson connects molecular mechanisms, cell behavior and biological evidence. Instead of memorizing isolated terms, follow what changes, what is measured, where the process occurs and why the outcome matters to a living system.
Big idea
A testable hypothesis predicts how an independent variable may affect a dependent variable. The independent variable is changed deliberately, the dependent variable is measured, and controlled variables are kept constant.
Learning goals
- Testable hypothesis: A testable hypothesis predicts how an independent variable may affect a dependent variable.
- Experimental variables: The independent variable is changed deliberately, the dependent variable is measured, and controlled variables are kept constant.
- Controls and replication: A control provides a baseline, while replication reveals natural variation and makes conclusions more reliable.
- Biological data: Tables, graphs, averages and ranges help reveal patterns without hiding variation.
- Uncertainty and conclusions: A conclusion must match the evidence and acknowledge measurement limits, sample size and alternative explanations.
Core concepts
1. Testable hypothesis
A testable hypothesis predicts how an independent variable may affect a dependent variable.
Observation or application: Plant growth is compared between a control group and a fertilized group.