Edexcel GCSE Biology key terms

A blood vessel that carries blood away from the heart.

Free from contaminating microorganisms; sterile conditions help prevent bacteria and fungi from growing in a culture.

A method of handling microorganisms that reduces contamination of a culture and its surroundings.

Reproduction involving a single parent, without the fusion of gametes, which normally produces genetically identical offspring.

The use of medical techniques to help someone achieve a pregnancy, often by controlling reproduction with hormones or handling eggs, sperm or embryos.

A simplified statement accepted for the purpose of making an estimate or calculation.

A fatty deposit in an artery wall that narrows the space through which blood flows.

The build-up of fatty material in artery walls, which narrows the space for blood flow and increases the risk of blood clots.

One of the two upper heart chambers that receives blood returning to the heart.

A machine that uses hot, pressurised steam to sterilise suitable equipment and growth media.

A condition caused by the immune system mistakenly attacking the body's own cells.

A plant hormone that controls growth by affecting processes such as cell elongation.

The long part of a neurone that carries electrical impulses away from the cell body.

A soil bacterium from which genes coding for insecticidal proteins can be transferred into crop plants.

One of the three domains; it contains the organisms commonly called bacteria, whose cells are prokaryotic.

A single-celled microorganism with cellular structures and processes that can be targeted by antibiotics.

A contraceptive that physically prevents sperm from reaching an egg.

One of the chemical units arranged in sequence along DNA; the order of these bases carries genetic information.

Placing quadrats at regular intervals along a line to record how organisms change in number with distance.

A non-cancerous tumour that remains contained in one area and does not invade surrounding tissues.

Cells in the pancreas that produce the hormone insulin.

A systematic influence on decisions, observations or reported results that can make a comparison unfair.

The variety of living organisms in an area.

The use of a living organism, such as a predator or parasite, to reduce the number of a pest species.

The mass of living material in an organism or group of organisms, often compared using dry mass.

A living component of an ecosystem, such as a plant, animal or microorganism.

The living parts of an ecosystem, such as plants, animals and microorganisms.