Foundations of Biological Science
Foundations of Biological Science
This domain tests how biological knowledge is built and the chemical and physical rules that underlie life: scientific inquiry and experimental design, measurement and microscopy, lab safety, water and pH, and the structure and function of biological macromolecules. Questions often ask you to identify variables, evaluate a conclusion, or predict a chemical property.
Core rules and concepts
- A hypothesis is a testable, falsifiable prediction; a theory is a broad, well-supported explanation. "Theory" does not mean guess.
- Controlled experiments manipulate one independent variable, measure a dependent variable, and hold confounders constant. A control group establishes the baseline; randomization reduces bias.
- Correlation does not establish causation. Sample size, replication, and blind or double-blind designs affect confidence.
- Magnification enlarges an image; resolution distinguishes two close points. Total magnification = ocular × objective.
- Water is polar, forms hydrogen bonds, has high specific heat and cohesion, and is a versatile solvent. pH = −log[H+], so a change of 1 pH unit is a 10-fold change in [H+].
- Carbohydrates, lipids, proteins, and nucleic acids are built from monomers or repeating units; protein shape determines function, and denaturation disrupts noncovalent interactions.
Worked example
A student claims a fertilizer increases plant height. Group A receives fertilizer; Group B receives the same volume of water. Both groups use the same soil, light, temperature, and plant species. Height is measured after four weeks. The independent variable is fertilizer presence; the dependent variable is height; Group B is the control. If Group A is taller, the student may conclude the fertilizer is associated with greater growth under these conditions-not that fertilizer causes growth in all plants. Replication and random assignment would strengthen the inference.
Traps
Calling a well-supported explanation "just a theory"; confusing magnification with resolution; changing multiple variables; treating a control as "no treatment" when a placebo or sham is needed; forgetting that pH is logarithmic; assuming all proteins denature reversibly.