AQA GCSE Biology key terms

A protein produced by lymphocytes that binds to and neutralises a particular toxin.

A carnivore that has no predators.

The total of the values divided by the number of values.

A blood vessel that carries blood away from the heart under relatively high pressure.

A mechanical device that takes over or supports the heart’s pumping action.

An electrical device that sends signals to the heart to correct an irregular heart rate.

Another name for selective breeding, emphasising that humans rather than the environment decide which organisms reproduce.

A set of procedures used to prevent unwanted microorganisms contaminating a culture, equipment or the surroundings.

A form of reproduction involving one parent, no fusion of gametes and no mixing of genetic information.

The relative amounts of gases in the air, including oxygen, carbon dioxide and gaseous pollutants.

An upper chamber of the heart that receives blood returning to the heart.

A group of plant hormones that affect growth; auxins can be used in rooting powders, tissue culture and selective weedkillers.

A population of bacteria with shared characteristics, such as resistance to a particular antibiotic.

A chart for separate categories, drawn with gaps between its bars.

Layers of dead cells around a stem that protect the living tissues underneath; on trees, this forms bark.

A contraceptive device, such as a condom or diaphragm, that physically prevents sperm reaching an egg.

A contraceptive method, such as a condom, that creates a physical barrier and reduces the transfer of pathogens during sexual contact.

The rate at which the body uses energy to maintain essential functions while at rest.

One of the four variable parts of a DNA nucleotide, represented by A, C, G or T.

A way an organism acts that helps it survive.

Describes a non-cancerous tumour that remains contained in one area and does not invade other tissues.

A consistent distortion in results caused by the way a study or sample is designed, selected, measured or reported.

An alkaline liquid made in the liver and stored in the gall bladder; it neutralises stomach acid and emulsifies fats in the small intestine.

A type of simple cell division in which one bacterial cell divides to form two daughter cells.

A universal system in which each species is given a two-part scientific name consisting of its genus and species.

The variety of all the different species of organisms on Earth or within a particular ecosystem.

A fuel made from recently living biological material, such as a crop.