Edexcel GCSE Biology key terms

All the organisms of one species living in a particular area.

A result showing that the substance being tested for is present in the sample.

Water that is safe to drink.

Apparatus that measures water uptake by a leafy shoot, allowing transpiration rate to be estimated.

Water that falls from clouds to the Earth's surface, such as rain, snow or hail.

Testing performed before a potential medicine is given to humans, using laboratory systems such as cultured cells and tissues and, where appropriate, live animals.

The feeding interaction in which one organism, the predator, catches and eats another, the prey.

The specific immune response when an antigen is encountered for the first time.

An organism, such as a plant or alga, that makes its own food and forms the first trophic level.

A substance formed by a chemical reaction.

An ovarian hormone that maintains the uterus lining after ovulation and inhibits FSH and LH.

A synthetic hormone that acts like progesterone.

A cell that does not have its genetic material enclosed within a nucleus.

A molecule made from a particular sequence of amino acids and involved in the structure or functioning of an organism.

An organism in a varied group of mostly single-celled organisms; some, including malaria parasites, cause disease.

The first coiled section of the nephron tubule after Bowman’s capsule, where glucose is reabsorbed.

The circulation carrying blood from the right side of the heart to the lungs and back to the left side.

A grid used to show the possible allele combinations in offspring from a genetic cross.

The opening in the centre of the iris through which light enters the eye.

A plant line that consistently produces offspring with the same form of a particular characteristic when self-pollinated.

A diagram whose bars show the biomass at successive trophic levels; a wider bar represents more biomass.

A frame enclosing a known area in which organisms can be counted or their coverage measured.

A test that shows whether a substance is present from an observation such as a colour change, rather than measuring its exact concentration.

A radioactive substance used to make the location of a target visible on a scan.

A mildly radioactive substance introduced into the body so that its distribution can be detected by a scanner.

A method of estimating the age of suitable material by measuring the decay of radioactive isotopes.

Treatment that uses ionising radiation to destroy tumour cells.