AP Science Placement Test Important Terms: Biology, Chemistry, Physics, Environmental Science
Biology Terms
Cell — The basic unit of life.
Organelle — A structure inside a cell that performs a specific job.
Nucleus — Controls cell activities and contains DNA.
DNA — Genetic material that carries instructions for traits.
Chromosome — A structure made of DNA containing genes.
Gene — A section of DNA that determines a trait.
Mitosis — Cell division that creates identical cells.
Meiosis — Cell division that creates sex cells.
Photosynthesis — Process plants use to make food from sunlight.
6CO_2 + 6H_2O \rightarrow C_6H_{12}O_6 + 6O_2Cellular Respiration — Process cells use to release energy from glucose.
Homeostasis — Maintaining stable internal conditions.
Osmosis — Movement of water through a membrane.
Diffusion — Movement of particles from high to low concentration.
Ecosystem — Living and nonliving things interacting in an area.
Producer — Organism that makes its own food.
Consumer — Organism that eats other organisms.
Decomposer — Organism that breaks down dead material.
Habitat — Place where an organism lives.
Species — Group of organisms that can reproduce together.
Evolution — Change in species over time.
Natural Selection — Organisms with helpful traits survive and reproduce more.
Biodiversity — Variety of living organisms in an area.
Enzyme — Protein that speeds up chemical reactions.
Protein — Molecule used for structure and functions in the body.
ATP — Main energy source for cells.
Membrane — Thin layer controlling what enters and leaves the cell.
Mutation — Change in DNA sequence.
RNA (Ribonucleic Acid) is a molecule that helps cells make proteins using instructions from DNA.
Main Functions of RNA
Carries genetic instructions from DNA
Helps build proteins
Assists cell activities
Types of RNA
mRNA (messenger RNA) — carries instructions from DNA to ribosomes
tRNA (transfer RNA) — brings amino acids to build proteins
rRNA (ribosomal RNA) — makes up ribosomes, where proteins are made
Chemistry Terms
Atom — Smallest unit of an element.
Element — Pure substance made of one type of atom.
Compound — Substance made of two or more elements chemically combined.
Molecule — Two or more atoms bonded together.
Proton — Positively charged particle in the nucleus.
Neutron — Neutral particle in the nucleus.
Electron — Negatively charged particle outside the nucleus.
Atomic Number — Number of protons in an atom.
Mass Number — Total number of protons and neutrons.
Periodic Table — Chart organizing elements by atomic number.
Ion — Charged atom formed by gaining or losing electrons.
Ionic Bond — Bond formed by transfer of electrons.
Covalent Bond — Bond formed by sharing electrons.
Chemical Reaction — Process where substances change into new substances.
Reactant — Starting substance in a chemical reaction.
Product — Substance formed in a chemical reaction.
Acid — Substance with pH below 7.
Base — Substance with pH above 7.
pH Scale — Measures how acidic or basic a substance is.
Catalyst — Substance that speeds up a reaction without being used up.
Solution — Mixture where one substance dissolves in another.
Solute — Substance being dissolved.
Solvent — Substance doing the dissolving.
Density — Mass per unit volume.
Matter — Anything with mass and volume.
Law of Conservation of Mass — Matter cannot be created or destroyed.
Mole — Unit used to count particles in chemistry.
Mixture — Combination of substances not chemically bonded.
Physical Change — Change in appearance without forming a new substance.
Chemical Change — Change that forms a new substance.
Boiling Point — Temperature where a liquid becomes a gas.
Melting Point — Temperature where a solid becomes a liquid.
Physics Terms
Force — A push or pull on an object.
F = maMass — Amount of matter in an object.
Weight — Force of gravity acting on an object.
Gravity — Force pulling objects toward Earth.
Motion — Change in position over time.
Speed — Distance traveled per unit of time.
Velocity — Speed in a specific direction.
Acceleration — Change in velocity over time.
Momentum — Quantity of motion an object has.
Inertia — Tendency of an object to resist changes in motion.
Friction — Force that opposes motion between surfaces.
Work — Force applied over a distance.
Energy — Ability to do work.
Kinetic Energy — Energy of motion.
Potential Energy — Stored energy.
Power — Rate of doing work.
Newton’s First Law — Objects stay at rest or in motion unless acted on.
Newton’s Second Law — Force depends on mass and acceleration.
Newton’s Third Law — Every action has an equal and opposite reaction.
Wave — Disturbance that transfers energy.
Frequency — Number of waves passing a point per second.
Wavelength — Distance between wave peaks.
Wave Speed — Speed a wave travels.
Electric Current — Flow of electric charge.
Voltage — Electrical potential difference.
Resistance — Opposition to electric current.
Ohm’s Law —
Circuit — Path through which electricity flows.
Magnetism — Force caused by magnetic fields.
Light Year — Distance light travels in one year.
Environmental Science Terms
Environment — All living and nonliving things around us.
Ecosystem — Organisms interacting with each other and their environment.
Biome — Large region with a specific climate and organisms.
Habitat — Natural home of an organism.
Population — Group of the same species in one area.
Community — Different populations living together.
Biodiversity — Variety of living organisms in an area.
Producer — Organism that makes its own food.
Consumer — Organism that eats other organisms.
Decomposer — Organism that breaks down dead matter.
Food Chain — Path of energy transfer between organisms.
Food Web — Multiple connected food chains.
Renewable Resource — Resource naturally replaced over time.
Nonrenewable Resource — Resource that cannot quickly be replaced.
Conservation — Protection and careful use of resources.
Sustainability — Using resources without harming future generations.
Pollution — Harmful substances entering the environment.
Air Pollution — Contamination of the atmosphere.
Water Pollution — Contamination of water sources.
Soil Pollution — Harmful chemicals in soil.
Climate Change — Long-term changes in Earth’s climate.
Global Warming — Increase in Earth’s average temperature.
Greenhouse Effect — Trapping of heat in Earth’s atmosphere.
Greenhouse Gases — Gases like carbon dioxide and methane that trap heat.
Deforestation — Cutting down forests.
Recycling — Reusing materials to reduce waste.
Carbon Footprint — Amount of greenhouse gases produced by activities.
Fossil Fuels — Coal, oil, and natural gas formed from ancient organisms.
Solar Energy — Energy from sunlight.
Wind Energy — Energy produced by moving air.
Hydroelectric Energy — Energy from moving water.
Ozone Layer — Atmospheric layer protecting Earth from UV radiation.
Extinction — Permanent disappearance of a species.
Invasive Species — Non-native species that harm ecosystems.