AQA GCSE Biology key terms

Questions and reasoned judgements about whether an action is right or wrong.

An organism whose cells contain a nucleus and other membrane-bound structures.

A cell whose genetic material is enclosed within a nucleus; animal and plant cells are eukaryotic.

The enrichment of water by mineral ions, often from fertiliser, which can cause an algal bloom and a fall in dissolved oxygen.

A change in the inherited characteristics of a population over successive generations.

A branching diagram representing scientists' conclusions about the evolutionary relationships among organisms.

A specialised boundary across which substances move between an organism and its surroundings, or between different parts of an organism.

The removal from an organism of waste products made by its metabolism, such as urea.

A reaction that transfers energy to the surroundings.

An increase in which the population is multiplied by the same factor during each equal time interval.

The permanent loss of a species after all its members have died.

An organism that lives in extreme conditions, such as very high temperature, pressure or salt concentration.

A diagram that shows biological relationships and the occurrence of an inherited characteristic through several generations of a family.

A severe and widespread shortage of food that causes hunger and malnutrition.

A heart valve that does not open fully or does not close properly, reducing the efficiency of blood flow through the heart.

The anaerobic respiration of glucose by yeast, producing ethanol and carbon dioxide.

The joining of the nuclei of a male and female gamete to form a fertilised egg cell.

An insoluble protein that forms a mesh during blood clotting.

A strip at the edge of an agricultural field that is left less intensively managed to provide habitat for organisms.

The circular area visible through a microscope at one time.

The fluid formed when small molecules are filtered out of the blood; useful substances can still be reabsorbed from it.

The removal of small molecules from the blood to form a fluid called filtrate.

A limit on the number or total mass of particular fish that may be caught in a specified area or period.

A population of fish of a particular species that is available to be caught in a defined area.

The long, whip-like part of a sperm cell that propels it towards an egg.

A light-emitting label that can be attached to an antibody so that the location of a bound target can be seen.

A range of lifelong physical, learning and behavioural difficulties caused by exposure to alcohol before birth.