GED Science: Lessons & Preparation Route
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Search lessons, illustrated explanations and study references within this exam.
Plan a fair experiment
Name the treatment, the response and the conditions that could also change the response. For a simple comparison, keep the relevant background conditions alike and vary the proposed cause.
Find a competing explanation
When the group with a treatment also differs in another way that could affect the outcome, the result is hard to attribute to the treatment. Use a comparison where the other difference is held fixed or balanced.
Read graph values before comparing change
Read the variable, unit, axis and tick spacing. A value is a coordinate; a change is the difference between two coordinates on the same series. A comparison of changes requires both endpoints for both series.
Compare changes per unit of time
Average rate is the measured change divided by elapsed time. For cumulative readings, subtract the starting value of the chosen interval first. Keep the time and measurement units consistent across comparisons.
Match a claim to the evidence
Read the claim for its outcome, population, comparison and conditions. An observation can support a local pattern. Stronger causal or universal wording requires a design and sample that address that stronger claim.
Separate precision from accuracy
Precision is closeness among repeated readings. Accuracy concerns closeness to an accepted reference. A small spread can coexist with an offset, so inspect repeats and a standard separately.
Follow energy through a food web
When the legend points arrows from food to consumer, read them in that direction. Use the specified paths to explain what might happen after a change, and state which other pathways or conditions could change the result.
Trace stabilizing feedback
Track a change in a measured condition, detection of the change, and a response that acts back on the condition. A stabilizing loop makes the original deviation smaller under the described conditions.
Read a single-gene cross
Use the inheritance conditions in the prompt. In a simple diploid cross with ordinary segregation, each parent contributes one allele. First find genotype probabilities, then use the stated dominance rule to predict the visible phenotype.
Explain a change in population composition
Selection can change how common a heritable trait is if individuals with that trait contribute a different share of surviving offspring. State the environmental condition and compare fractions across generations.
Distinguish position, velocity and acceleration
Position locates an object relative to a reference point. Displacement is a signed position change, while distance adds the lengths traveled. Net force determines acceleration, which describes how velocity changes.
Keep an energy account
Identify the system and where its energy can go. Mechanical energy combines kinetic and potential energy. It may decrease when energy becomes thermal or leaves the system, even while energy is conserved overall.
Track mass across a boundary
Include every substance that remains in the measured system, even gas. In ordinary chemical and physical changes, a closed collection conserves total mass. An open measurement can change when matter crosses its boundary.
Use the final solution volume
Mass concentration compares the mass of dissolved solute with total solution volume. When pure solvent is added without loss of solute, the solute amount stays fixed while the total volume increases.
Trace runoff and infiltration
Rain can run over land, enter the ground, evaporate or remain stored. Under similar rainfall, an impervious surface tends to restrict infiltration and can send more water toward an outlet.
Use daylight evidence to explain seasons
Earth’s axis stays tilted in roughly the same direction in space over a year. As Earth orbits the Sun, the hemisphere tilted toward the Sun receives more direct sunlight and has longer days at comparable middle latitudes.
Original foundation practice for selected skills across three science domains.