Edexcel GCSE Biology key terms

The volume of oxygen taken up by living organisms per unit time, used here as a measure of their rate of aerobic respiration.

The amount of photosynthesis taking place per unit of time.

The amount of substrate used up or product formed per unit time in an enzyme-controlled reaction.

The return of a substance from fluid in the kidney to the blood.

A starting substance that is changed during a chemical reaction.

A substance added to a sample to produce a chemical reaction that can reveal whether another substance is present.

A cell or group of cells that detects a stimulus or change in a condition.

An allele whose characteristic is expressed only when no dominant allele is present in the pair.

An allele that affects the phenotype only when two copies are present.

A blood cell that transports oxygen using haemoglobin.

A sugar that reacts with heated Benedict’s solution; examples include glucose and lactose.

A group whose measurements provide the values used for comparison on a percentile chart.

The neural pathway followed by impulses during a reflex response.

A rapid, automatic response to a stimulus that occurs without conscious control.

Planting trees to restore woodland or forest.

The bending of light as it passes from one material into another, such as when it enters the cornea.

A response in which the recipient's immune system attacks a transplanted organ because it recognises it as different from the body's own tissues.

A measure calculated as $1/t$ when different trials all reach the same fixed end point.

A neurone within the central nervous system that connects other neurones, such as sensory and motor neurones.

A blood vessel that carries blood into a kidney.

A blood vessel that carries blood away from a kidney.

The replacement of damaged, dead or worn-out cells with new cells.

A repeat of a measurement made under the same conditions, used to identify anomalous results and make a mean more reliable.

The ability of an organism to survive exposure to a substance that would normally kill it; antibiotic-resistant bacteria can survive an antibiotic that kills susceptible bacteria.

The ability to distinguish two points that are close together as separate points.

The process in living cells that releases energy from glucose; aerobic respiration also produces carbon dioxide.

A sealed apparatus that measures a change in gas volume as an organism takes up oxygen.