Edexcel GCSE Biology key terms

The region at the back and base of the brain that coordinates muscular activity, balance and posture.

The two large, folded halves at the top and front of the brain that control conscious thought, memory, language, sensory awareness and voluntary movement.

The difference between the final and initial values of a quantity; it may be positive or negative.

The final mass minus the initial mass; it is positive for a gain and negative for a loss.

A substance that helps protect the body by killing or breaking down pathogens.

A sexually transmitted bacterial infection that often causes no symptoms and can be treated with antibiotics.

A green pigment that absorbs light energy for photosynthesis.

A structure containing chlorophyll where photosynthesis occurs.

A bacterial disease that causes diarrhoea.

The main closed loop of DNA in a bacterium, carrying most of its genetic information and lying free in the cytoplasm.

A long, packaged DNA molecule that carries many genes.

Tiny hair-like structures on cells lining the airways that move mucus towards the throat.

A cell forming part of a sheet that lines a surface or body structure and bears moving cilia.

Severe scarring of the liver that usually cannot be reversed.

The organisation of organisms into groups according to their characteristics and evolutionary relationships.

Carefully controlled testing of a potential medicine in human volunteers and patients.

A fertility drug that stimulates the pituitary gland to release more follicle-stimulating hormone and luteinising hormone.

A cell or organism genetically identical to another because it was produced from one parent without sexual reproduction.

The part of a gene whose base sequence determines the amino acid sequence of a protein.

The inheritance pattern in which both alleles in a heterozygous genotype are fully expressed in the phenotype.

A group of three bases on mRNA that specifies an amino acid or signals the end of translation.

A tube in the kidney through which fluid passes as it becomes urine; water can be reabsorbed from it into the blood.

A colour vision deficiency in which a person cannot distinguish certain colours in the usual way because one or more types of cone do not respond normally.

Burning a substance, such as wood or a fossil fuel, which releases carbon dioxide into the atmosphere.

An organism from which two or more groups have evolved.

A disease caused by a pathogen that can spread between organisms, either directly or indirectly.

All the populations of different species living and interacting in the same area.