AQA GCSE Combined Science Trilogy key terms

A separation process in which a liquid is vaporised and its vapour is cooled and condensed so that the liquid can be collected.

Something that draws attention away from the task being carried out.

The pattern of where a species occurs within an area.

The molecule that carries genetic information. It is a polymer made of two strands forming a double helix.

The copying of DNA to produce two exact copies of each chromosome before cell division.

A broad classification group above kingdom. The three domains are Archaea, Bacteria and Eukaryota.

An allele expressed in the phenotype even when only one copy is present.

An allele expressed in the phenotype when one copy is present.

The amount of a drug given at one time.

A representation of electrons using different symbols to show which atoms the electrons originally came from.

A trial in which neither the participants nor the staff conducting the trial know who receives the drug and who receives the placebo during testing.

A transport system in which blood passes through the heart twice during one complete circuit: once through the lungs and once through the rest of the body.

The shape formed by two strands wound around each other.

A resistive force that opposes an object's motion through a fluid. Air resistance is drag acting in air.

Transmission of pathogens in droplets released during coughing or sneezing, which another person may breathe in.

A prolonged period of unusually low rainfall that can cause water shortages.

A substance used as a medicine to treat disease or relieve symptoms.

Able to be drawn into a wire.

A state in a closed system where the forward and reverse reactions continue at equal rates, so the amounts of reactants and products remain constant.

The reference electrical potential assigned to the Earth: 0 V.

The green-and-yellow-striped safety wire connected to an appliance’s metal case. It is at earth potential (0 V) and carries current only if there is a fault.

A community of organisms interacting with one another and with the non-living conditions of their environment.

A muscle or gland that carries out a response: a muscle contracts, while a gland secretes a substance such as a hormone.

How effectively a drug produces its intended treatment effect.

The fraction of the total energy input that is transferred usefully by a device or system.

The liquid separated from sewage sludge during sedimentation, which still requires further treatment.

A change in shape that is reversed when the deforming forces are removed: the object returns to its original shape and length.