OCR GCSE Biology A key terms

The biological polymer that stores genetic information in cells; its information provides a code used to make proteins.

An enzyme that joins DNA fragments into a continuous molecule.

The process of copying DNA to make an identical DNA molecule before cell division.

Determining the order of nucleotide bases in a section of DNA.

An animal whose breeding and way of life have been managed by humans for purposes such as food, work or companionship.

An allele that produces its associated phenotype when one or two copies are present.

An allele whose associated phenotype is seen when one or two copies are present in a simple dominant–recessive pattern.

A person who provides cells, tissue or an organ for transplantation.

A period when a viable seed does not germinate, even though it may later be able to grow.

The measured quantity of a medicine given at one time or over a stated period.

A trial in which neither the participants nor the researchers assessing them know who has received the medicine or the comparison treatment until the results have been collected.

A circulation in which blood passes through the heart twice during one complete journey around the body.

The shape formed when two strands wind around one another in a spiral.

A community of organisms interacting with each other and with the non-living parts of their environment.

Tourism based on experiencing the natural environment that can support conservation and local communities when it is managed sustainably.

A muscle or gland that produces a response after receiving a signal from a coordination centre.

How well a medicine produces its intended beneficial effect.

The removal of undigested food from the digestive system as faeces.

A form of microscopy that uses a beam of electrons rather than visible light to produce highly resolved images.

A test that uses antibodies linked to an enzyme to detect a particular antigen, often through a colour change.

An early stage of development formed when a fertilised egg divides.

A stem cell from an early embryo that can differentiate into almost any type of specialised body cell.

A cloudy mixture of tiny droplets of one liquid dispersed in another; a white emulsion is a positive result in the ethanol test for lipids.

An organ that produces and releases hormones into the bloodstream.

The collection of hormone-producing glands that coordinates and controls processes in the body.

A chemical reaction that takes in energy from its surroundings overall.

A long-term alteration in environmental conditions, including changes in temperature and rainfall patterns.