GED Science key terms

A testable, falsifiable prediction about what will happen under specified conditions. It is stated before an experiment and evaluated against the resulting data.

The factor a researcher deliberately changes or manipulates in an experiment. Its effect on the outcome is what the study is designed to measure.

The factor that is measured or observed in an experiment. It is expected to respond to changes in the independent variable.

The comparison group in an experiment that does not receive the treatment being tested. It shows what would happen without the independent variable.

A statistical relationship in which two variables tend to change together. Correlation alone does not prove that one variable causes the other.

The process by which plants, algae, and some bacteria use light energy to convert carbon dioxide and water into sugar, releasing oxygen as a byproduct.

The process cells use to release energy from sugar, typically consuming oxygen and producing carbon dioxide and water. It is essentially the reverse of photosynthesis.

A sequence showing how energy moves from producers to consumers as organisms eat one another. Energy decreases at each step because much is lost as heat.

Information gathered directly through the senses or with instruments, such as a measurement, color change, or sound; observations are the raw evidence scientists use to draw conclusions.

A logical explanation or interpretation based on observations and prior knowledge rather than on direct sensing; inferences go beyond what was actually observed.

A well-tested, broad explanation for a set of related observations, supported by much evidence and accepted by most scientists; it is not a guess.

A systematic error or slant that pushes results or interpretations in a particular direction, often caused by how a study is designed, measured, or reported.

Recorded observations or measurements that scientists collect and analyze; data can be numbers or descriptions and are used as evidence to support or reject a hypothesis.

The smallest living unit of an organism; cells have a membrane, contain genetic material, and carry out life processes such as obtaining energy and making proteins.

The molecule that carries genetic instructions in living things; DNA is made of two strands twisted together and its sequence of bases encodes information for building proteins and traits.

A section of DNA that provides instructions for making a protein or for controlling a trait; genes are passed from parents to offspring and can exist in different versions.

The process by which individuals with traits better suited to their environment tend to survive and reproduce more, so those helpful traits become more common in later generations.

All the living organisms in a particular area together with the nonliving parts of their environment, such as water, soil, air, and sunlight; organisms interact with each other and with these parts.

A diagram or model showing many interconnected food chains in an ecosystem, illustrating how energy and matter move from producers to various consumers and decomposers.

The ability of a living thing to keep its internal conditions, such as temperature or water balance, within a stable range even when the outside environment changes.

The ongoing set of processes that change rocks among igneous, sedimentary, and metamorphic forms through melting, cooling, weathering, erosion, deposition, compaction, and heat and pressure.

The scientific model that Earth's outer shell is broken into large moving plates; their interactions cause earthquakes, volcanoes, mountain building, and the shifting of continents over time.

The breakdown of rocks and other materials at or near Earth's surface by physical, chemical, or biological processes; it does not involve transporting the broken pieces away.

The movement or carrying away of weathered rock, soil, and other materials by agents such as water, wind, ice, or gravity; it often follows weathering and can reshape landscapes.

The continuous movement of water through evaporation, condensation, precipitation, and collection on Earth; it transfers water between the oceans, atmosphere, land, and living things.

The warming of Earth's surface and lower atmosphere when certain gases trap heat that would otherwise escape to space; this natural process helps keep Earth warm enough for life.

The Sun and all the objects that orbit it, including planets, moons, asteroids, and comets; gravity holds the system together and keeps objects in orbit.

A force of attraction between any two objects that have mass; on Earth it pulls objects toward the planet's center and keeps the Moon and satellites in orbit.

The typical weather conditions of a region over many years, including average temperature and precipitation patterns; climate differs from day-to-day weather and can be affected by the greenhouse effect.

The changing appearance of the Moon as seen from Earth, caused by the relative positions of the Sun, Earth, and Moon; the Moon does not actually change shape.