Edexcel GCSE Biology key terms

The body’s network of cells, tissues and organs that recognises and defends against pathogens.

The process of producing immunity or increased resistance to an infectious disease, commonly through vaccination.

The ability to respond rapidly to a pathogen's antigens following an earlier exposure, helping to prevent disease.

The attachment of an early embryo to the lining of the uterus.

Breeding between closely related organisms, which increases the chance that offspring inherit two copies of a harmful recessive allele.

The factor deliberately changed during an investigation; here, it is the concentration of the sucrose solution.

A species whose presence, absence or abundance provides evidence about environmental conditions, such as pollution.

A single living thing.

A state of illness, weakness or poor health, especially one that is persistent.

The passing of genetic information, which influences characteristics, from parents to offspring.

A feature that can be passed from parents to offspring through genes.

The mass of a sample before it is placed in the test solution.

A small tool used to pick up and transfer microorganisms between cultures.

A hormone made by the pancreas that helps glucose move from the blood into body cells, where it can be used for energy.

A small device attached to the body that delivers insulin.

A condition in which body cells do not respond normally to insulin.

A relationship in which organisms depend on other organisms for resources or processes needed for survival or reproduction.

The conditions surrounding the cells inside an organism, including temperature and the concentrations of water and glucose.

The stage of the cell cycle when a cell grows and copies its DNA before division.

A relationship in which one quantity is proportional to the reciprocal of another, so their product remains constant.

A relationship in which a quantity is proportional to the reciprocal of the square of the distance: $1/d^2$.

An ART procedure in which an egg is fertilised outside the body before the resulting embryo is transferred into the uterus.

An automatic action that does not require conscious thought, such as the normal control of heart rate.

A chemical test in which iodine turns blue-black if starch is present and remains yellow-brown if it is not detected.

The coloured ring of muscle that controls how much light enters the eye by changing the diameter of the pupil.

One of two organs that filter blood and produce urine.

A treatment that uses a machine to remove waste substances and excess water from a person's blood when their kidneys cannot do so sufficiently.