AQA GCSE Biology key terms

The process in which humans choose plants or animals with desired genetic characteristics and breed them so that these characteristics become more common over generations.

The return of particular useful substances from the kidney tubules to the blood according to the body’s needs.

A nerve cell that carries electrical impulses from a receptor towards the central nervous system.

Waste water containing human waste and other organic material.

One of the chromosomes involved in determining biological sex; in humans these are X and Y.

An infection that can pass from one person to another through sexual contact.

Reproduction in which male and female gametes fuse, mixing genetic information and producing varied offspring.

Rapid, involuntary contractions of skeletal muscles that help warm the body.

An unwanted effect of a treatment in addition to its intended effect.

A perforated end wall between phloem sieve-tube cells through which dissolved sugars can pass.

An observable feature that suggests a plant is unhealthy, such as leaf spots or stunted growth.

The wearing away and removal of soil by agents such as water.

A cell whose structures are adapted to enable it to carry out a particular function.

The formation of a new species from an existing population.

The most specific Linnaean rank; it identifies one particular kind of organism.

The geographical areas in which a species occurs.

The matching of an enzyme's active site to a particular substrate because their shapes are complementary.

A chemical agent that kills or disables sperm.

Leaf tissue with loosely arranged cells and air spaces that allow gases to diffuse through the leaf.

A reproductive unit produced by a fungus that can be dispersed and start a new infection.

A community in which species and environmental factors are sufficiently balanced for population sizes to remain fairly constant.

A coloured chemical used to increase contrast so that otherwise colourless cell structures are easier to distinguish.

A way of writing a number as $a \times 10^n$, where $1 \leq a < 10$ and $n$ is an integer.

The level of material comfort experienced by a person or population, associated with the quantity of goods and services used.

An insoluble carbohydrate into which plants convert glucose for storage.

A type of drug used to lower blood cholesterol, slowing the build-up of fatty material in arteries.

A cell that has not yet become specialised and can divide to produce more stem cells and cells that differentiate into specialised types.