Biology key terms

A characteristic or exposure linked to an increased rate of a disease, without making the disease inevitable.

An enzyme that binds to DNA and joins RNA nucleotides together to produce an mRNA strand.

A retinal photoreceptor that is very sensitive to dim light but does not provide colour vision.

A specialised plant cell with a long projection that provides a large surface area for absorbing water and mineral ions from the soil.

A preparation containing a growth-promoting hormone that encourages a plant cutting to develop roots.

Replacing a number with a nearby value containing fewer digits while keeping its size as close as required.

Heating with precautions suited to the apparatus and material: a Bunsen burner provides a direct flame, while a water bath warms a sample indirectly. Check temperature and handle hot equipment safely.

An illness caused by Salmonella bacteria, usually after the bacteria are swallowed in contaminated food.

A smaller group selected from a population to provide data about that population.

The number of independent individuals, organisms, objects or samples included in an investigation.

Counting a manageable part of a habitat to help estimate what is present in the wider area.

Safe disposal and treatment of human waste so that it does not contaminate water or food.

The dried protective covering that develops over a clot at the skin's surface.

The relationship between a represented or measured distance and the corresponding actual distance.

A labelled line on an image whose length represents a stated real distance in the specimen.

An electron microscope that scans a specimen's surface and uses scattered electrons to reveal its surface form.

A graph in which each plotted point represents paired values for two numerical variables.

The sharing of scientific methods, evidence, conclusions and their implications in a form an intended audience can understand.

A development in scientific knowledge, methods or understanding.

A clear, labelled line drawing that records structures actually observed in a specimen.

A labelled drawing that records the structures actually observed in a specimen, using clear lines rather than shading.

A way of investigating a question, such as collecting observations or carrying out controlled experiments.

A simplified representation of a system that selects important features and rules for how they interact.

A measurable property expressed as a number, with a unit where appropriate.

A question about the natural world that could, in principle, be investigated using observations, measurements or experiments.

A well-supported scientific explanation that accounts for observations and can be tested against evidence.

The tough white outer layer that protects the eyeball.