Science
Science practices and content
Science questions emphasize how science works as much as facts. Understand hypotheses, variables, control groups, and experimental design. Identify the independent variable (what the experimenter changes), the dependent variable (what is measured), and controlled variables (kept the same). Read tables and graphs carefully, including axis labels and units. Content may include cells, heredity, ecosystems, matter and energy, forces and motion, Earth systems, and body systems, but most questions give you the information in a passage, diagram, or data table.
Traps
Correlation is not causation; a graph showing two trends together does not prove one caused the other. Words like proves are usually too strong-evidence supports or suggests. Do not confuse the independent and dependent variables. Ignore the control group and you may misread the conclusion. Check whether a sample is large enough and whether the data are consistent. Also watch unit scales on graphs and distinguish observations from inferences.
Worked example
A student grows plants with 0, 5, and 10 grams of fertilizer while keeping light, water, and soil the same. The independent variable is fertilizer amount; the dependent variable is plant growth; controlled variables are light, water, and soil. If taller plants occur with more fertilizer, the data support the hypothesis that fertilizer affects growth, but one experiment does not prove it universally. Rule of thumb: ask what changed, what was measured, and what was held constant.