Edexcel GCSE Biology key terms

A technique that uses multiple X-ray measurements and computer processing to produce images of structures inside the body, including the brain.

A waxy, water-resistant layer covering the epidermis of a leaf and reducing water loss from its surface.

Division of the cytoplasm and cell membrane to form two separate cells.

A new cell formed when a parent cell divides.

The removal of the nitrogen-containing part of an amino acid during its breakdown in the liver.

The breakdown of dead organisms, waste or other biological material by decomposers or their enzymes.

A microorganism, such as a bacterium or fungus, that breaks down dead organic material and waste.

The breakdown of dead organic material and waste into simpler substances by decomposers.

A change in an enzyme's shape that prevents it from working properly, often caused by excessive heat.

Permanently changed in shape so that an enzyme's active site is no longer complementary to its substrate.

A long extension of a sensory neurone that carries impulses from receptor endings towards the cell body.

The conversion of soil nitrates into nitrogen gas by denitrifying bacteria, reducing the nitrates available to plants.

The factor measured in response to the independent variable; here, it is the change in mass of the potato tissue.

The layer of skin beneath the epidermis that contains blood vessels and sweat glands.

The removal of dissolved salts from seawater or other salty water.

A substance that breaks down the fatty cell membrane, helping to release DNA from cells.

The work needed to turn a promising substance into a medicine suitable for thorough testing and possible use in patients.

A test on a plant sample used to help identify the pathogen responsible for disease.

The distance across a circle through its centre; it is twice the radius.

Frequent passing of loose or watery faeces.

The process by which an unspecialised cell changes to become adapted for a particular function.

The net movement of particles from a region of higher concentration to a region of lower concentration because of their random movement.

The distance particles must travel across an exchange surface, such as from air in an alveolus into the blood.

A cell containing two sets of chromosomes, with one chromosome of each pair inherited from each parent.

A relationship in which one quantity changes by the same factor as another, so their ratio remains constant.

The stage in which a substance with the potential to become a medicine is found or designed.

A condition that persistently disrupts the normal functioning of the body or mind.