AQA GCSE Combined Science Trilogy key terms

A region containing no matter. Electromagnetic waves can travel through it without needing particles to carry them.

A decision about the importance or seriousness of something, rather than a direct measurement; for example, deciding how much importance to give habitat damage compared with energy use.

Differences in the characteristics of individuals within a population of the same species.

Male sterilisation in which the sperm ducts are cut or blocked so sperm cannot enter the semen.

A carrier, usually a bacterial plasmid or a virus, used to transfer a gene into a target cell in genetic engineering.

A quantity that has both magnitude (size) and direction.

A blood vessel that carries blood towards the heart.

The speed of an object in a specified direction, measured in metres per second (m/s).

The movement of air into and out of the lungs.

A lower chamber of the heart that pumps blood out of the heart.

A finger-like projection of the small intestine's lining that increases the surface area for absorption.

An infectious agent that reproduces inside living host cells, often damaging or destroying them.

A measure of a liquid’s resistance to flow. A highly viscous liquid flows less easily.

The range of electromagnetic waves detectable by human eyes, extending from red to violet.

The release of gases from volcanoes, which is thought to have helped form the Earth’s early atmosphere.

A meter that measures potential difference between two points and is connected in parallel across the component being tested.

The space occupied by an object or sample, measured in cubic metres, m³, or smaller units such as cm³.

Water that has been used in homes, agriculture or industry and contains waste substances that may need removing.

The continuous movement of water between the atmosphere, land, bodies of water and living organisms.

Water incorporated into the crystal structure of a salt.

Water in its gaseous state.

The unit of power. A power of one watt means that one joule of energy is transferred each second: $1\text{ W} = 1\text{ J/s}$.

A travelling disturbance that transfers energy from one place to another without transferring the material of the medium from end to end.

A line joining points at the same stage of a wave's cycle, such as points along a crest.

The distance between corresponding points on consecutive waves, such as from one crest to the next, measured in metres.

The speed at which a wave, and the energy it carries, travels through a medium, measured in metres per second (m/s).

An acid that is only partially ionised in aqueous solution.

The force acting on an object due to gravity.