Edexcel GCSE Biology key terms

The quantity of an organism in a particular area, measured using a consistent method such as a count or percentage cover.

A characteristic that develops during an organism’s lifetime because of its environment rather than being inherited genetically.

A cap-like structure in the head of a sperm cell that contains enzymes used to break down substances in the egg's jelly coat.

The region of an enzyme with a shape that is complementary to its substrate and where the reaction is catalysed.

Movement of a substance against its concentration gradient using energy released by respiration.

Tuberculosis that is causing symptoms and can spread from a person with an infection in the lungs.

A characteristic that helps an organism survive and reproduce in a particular environment.

A hormone released by the pituitary gland that increases the permeability of the kidney's collecting ducts to water.

A chemical messenger made by the adrenal glands that prepares the body for fight or flight.

An unspecialised cell retained in a developed animal that usually produces a limited range of related specialised cells.

The release of energy from food using oxygen.

The clumping together of pathogens when antibodies bind to their antigens, which makes the pathogens easier for phagocytes to destroy.

Materials and resources used to produce food, such as seeds, fertiliser, animal feed and fuel.

Acquired immune deficiency syndrome; a collection of serious illnesses associated with advanced HIV infection.

The spread of a pathogen through the air, for example in droplets breathed out by a person or in wind-blown fungal spores.

A rapid increase in the growth of algae in water.

An alternative version of a gene.

One of the tiny air sacs in the lungs where gases are exchanged between air and blood.

A small molecule used to build proteins. Amino acids contain nitrogen.

An enzyme that catalyses the breakdown of starch into smaller sugars.

Respiration that transfers energy from glucose without using oxygen; glucose is only partially broken down.

A procedure that widens a narrowed artery, usually using a balloon and often a stent.

A medicine that treats bacterial infections by interfering with processes in bacterial cells.

A protein made by lymphocytes that binds to a specific, complementary antigen.

A triplet of bases on tRNA that pairs with a complementary codon on mRNA.

A molecule, often on a cell’s surface, with a shape that a particular antibody can recognise and bind to.

A substance that kills microorganisms or stops their growth.