AQA GCSE Biology key terms

A nitrogen-containing ion absorbed from the soil and needed by plants to produce amino acids and then proteins.

DNA that does not code for a protein; some of it controls whether genes are switched on or off.

A disease that cannot be passed from one organism to another; many such diseases are long-lasting and may worsen over time.

A defence that acts against many different pathogens rather than recognising one particular antigen.

A repeating unit of DNA containing a sugar, a phosphate group and one base.

A sub-cellular structure that contains the chromosomes in plant and animal cells.

An ovarian hormone that helps rebuild and maintain the uterus lining, inhibits FSH and, at a high level, stimulates LH release.

The nerve that carries electrical impulses from the eye to the brain.

The condition or value at which an organism or process performs best.

The dose that gives the best balance between producing the intended effect and limiting harmful side effects.

The temperature at which an enzyme-controlled process has its maximum rate.

A tenfold difference in size or quantity; two orders of magnitude represent a factor of $10^2=100$.

An aggregation of different tissues working together to perform a specific function.

A carbon-based molecule, such as glucose, a fat or a protein, that can form living tissue or act as a fuel.

A single living thing.

A group of organs working together to perform one or more major functions in an organism.

The surgical replacement of a failed or damaged organ with a functioning organ from a donor.

The net movement of water through a partially permeable membrane from a dilute solution to a more concentrated solution.

A value that lies noticeably away from the overall pattern of the other data points.

A female reproductive organ that produces eggs and oestrogen.

Catching fish faster than their population can replace them through reproduction.

The release of a mature egg from an ovary.

A reaction in which a substance combines with oxygen or loses electrons; glucose is completely oxidised in aerobic respiration but incompletely oxidised in anaerobic respiration.

The amount of extra oxygen the body needs after exercise to react with accumulated lactic acid and remove it from cells.

A medicine that relieves pain or other symptoms without killing the pathogen causing an infectious disease.

Leaf tissue near the upper surface whose closely packed cells contain many chloroplasts for photosynthesis.

A membrane that allows some substances to pass through but prevents others from doing so.