Biology key terms

A machine that uses hot, pressurised steam to sterilise suitable equipment and growth media.

A condition caused by the immune system mistakenly attacking the body's own cells.

An automatic response that occurs without conscious control.

A group of plant hormones that affect growth; auxins can be used in rooting powders, tissue culture and selective weedkillers.

A group of plant hormones that regulate growth, including the elongation of cells involved in tropisms.

The long part of a neurone that carries electrical impulses away from the cell body.

A soil bacterium from which genes coding for insecticidal proteins can be transferred into crop plants.

One of the three domains; it contains the organisms commonly called bacteria, whose cells are prokaryotic.

A layer of bacterial growth spread across the surface of a nutrient agar plate.

A population of bacteria with shared characteristics, such as resistance to a particular antibiotic.

A single-celled microorganism with cellular structures and processes that can be targeted by antibiotics.

A chart for separate categories, drawn with gaps between its bars.

Layers of dead cells around a stem that protect the living tissues underneath; on trees, this forms bark.

A method such as a condom that creates a physical barrier, reducing the exchange of bodily fluids during sexual contact.

A contraceptive device, such as a condom or diaphragm, that physically prevents sperm reaching an egg.

A contraceptive method, such as a condom, that creates a physical barrier and reduces the transfer of pathogens during sexual contact.

The rate at which the body uses energy to maintain essential functions while at rest.

The minimum rate of energy-releasing chemical reactions needed to keep the body functioning while at rest.

One of the four variable parts of a DNA nucleotide, represented by A, C, G or T.

A way an organism acts that helps it survive.

A strip across a habitat sampled using quadrats, either continuously or at regular intervals along a transect line.

A helpful outcome or advantage of an action.

Describes a non-cancerous tumour that remains contained in one area and does not invade other tissues.

A non-cancerous tumour that remains contained in one area and does not invade surrounding tissues.

Cells in the pancreas that produce the hormone insulin.

A consistent distortion in results caused by the way a study or sample is designed, selected, measured or reported.

A disc shape that curves inwards on both faces, giving a large surface area compared with its volume.