AQA GCSE Combined Science: Synergy key terms

Partly decomposed plant material that accumulates over long periods in waterlogged conditions where there is little oxygen.

A growing material that contains no peat, reducing the demand to extract peat from peatlands.

Evaluation of scientific research by other scientists with relevant expertise before publication.

The ability of radiation to pass through a material.

A person's judgement of how likely or serious a harmful event is, which may differ from estimates based on scientific evidence.

The percentage of a compound’s total mass contributed by a particular element.

The change in a measurement expressed as a percentage of its initial value. For mass, $\text{percentage change} = \frac{\text{final mass} - \text{initial mass}}{\text{initial mass}} \times 100$.

Correct use of a contraceptive method every time it is needed.

A horizontal row of the periodic table. Its number equals the number of occupied electron shells in an atom of an element in that row.

A repeating pattern. In the periodic table, similar chemical properties recur as atomic number increases.

A magnet that produces its own persistent magnetic field without requiring an electric current.

A fluid-filled compartment in a plant cell that contains cell sap and helps support the cell.

A measure of how acidic or alkaline a solution is. A lower pH corresponds to a higher hydrogen ion concentration.

A white blood cell that engulfs and digests pathogens.

The process in which a white blood cell engulfs and digests a pathogen.

The observable characteristics of an organism, resulting from its genes and their interaction with the environment.

Plant transport tissue made of tubes of elongated living cells that carry cell sap containing dissolved sugars and other nutrients.

The process by which plants and algae use light energy to make glucose from carbon dioxide and water, releasing oxygen.

A change in which no new substance is formed. A change of state is a physical change: reversing it restores the material’s original properties.

The uptake of metal compounds from soil by plants; this is the uptake stage used in phytomining.

Extraction using plants that absorb metal compounds, followed by harvesting and burning the plants to produce ash containing those compounds.

A coloured substance. Plant leaves contain chlorophyll and other pigments that can be separated by chromatography.

A gland in the brain that secretes several hormones, including hormones that stimulate other endocrine glands.

A treatment that resembles the tested medicine but contains none of its active drug, used for comparison in a trial.

A build-up of fatty material inside an artery that can narrow the space through which blood flows.

The mainly water-based liquid component of blood that transports blood cells, platelets and dissolved substances.

A small, circular piece of DNA found in bacterial cells that can be used as a vector in genetic engineering.