AQA GCSE Combined Science Trilogy key terms

The phase that stays in place during chromatography; in GCSE paper chromatography, this is the chromatography paper.

An undifferentiated cell that can produce many more cells of the same type and can give rise to certain other cell types through differentiation.

A small supporting tube inserted into an artery to hold it open and improve blood flow.

A transformer that decreases the potential difference between its input and output.

A transformer that increases the potential difference between its input and output.

Surgery intended to permanently prevent reproduction by blocking or cutting reproductive ducts.

A change in the internal or external environment that can be detected by a receptor.

A pore in a leaf's surface through which gases, including water vapour, can diffuse; its opening is controlled by guard cells.

The total distance a vehicle travels from when the driver notices a hazard until the vehicle stops: thinking distance plus braking distance.

A genetically different form of a microorganism within a species.

An acid that is completely ionised in aqueous solution.

A physical part or feature of an organism that helps it survive in its environment.

A structure within a cell, such as a nucleus, mitochondrion or ribosome.

The change of state directly from solid to gas, without becoming liquid first.

A small number written below and to the right of a symbol or bracket in a formula, showing how many atoms or groups are present.

The substance on which an enzyme acts.

A collision between reacting particles that results in a chemical reaction.

A gas, $\mathrm{SO_2}$, that causes respiratory problems and contributes to acid rain.

The total area of a solid exposed to its surroundings and available for contact with another reactant.

The surface area of an object divided by its volume. Smaller pieces of the same shape have a larger surface area to volume ratio.

Everything outside the reacting chemicals that can exchange energy with them, such as the surrounding solution, container and air.

Using resources in a way that allows them to remain available for future generations.

Development that meets the needs of current generations without compromising the ability of future generations to meet their own needs.

A device that opens or closes a conducting path in a circuit.

A representation of a chemical reaction using the chemical symbols and formulae of the reactants and products.

A change in the body caused by a disease, such as pain or fever.

A junction between neurones containing a tiny gap across which neurotransmitters carry the signal.