Combined Science key terms

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

A measurable quantity that has both magnitude and an associated direction.

A blood vessel that carries blood towards the heart.

Speed 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.

The unit of potential difference. One volt means one joule of energy is transferred per coulomb of charge: $1\text{ V} = 1\text{ J/C}$.

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.

Waist circumference divided by hip circumference, with both measured in the same units; an indicator of fat distribution.

Waist circumference divided by hip circumference, with both measurements in the same units; it indicates how body fat is distributed.

Energy transferred in a way that does not serve the intended purpose of a device or process.

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 from a point on one wave to the equivalent point on the adjacent wave. Its symbol is $\lambda$ and its unit is the metre (m).

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

The speed of a travelling wave together with its direction of travel. Wave speed is measured in metres per second (m/s).