OCR GCSE Combined Science A key terms

The preserved remains or traces of an organism from the past, such as bones, footprints or burrows.

Coal, oil or natural gas: a fuel formed from ancient organic material, with energy in its chemical store.

The collection of known fossils and their positions in geological time, providing evidence of past life and its changes.

A mixture collected during fractional distillation whose components have similar boiling points.

Separation of a mixture of liquids with different boiling points using a fractionating column and condensation.

A tower used for fractional distillation, with a high temperature at the bottom and a lower temperature at the top.

A representation of one object showing the forces acting on it as labelled arrows. Arrow direction shows force direction and arrow length represents force size.

A diagram showing all the forces acting on one chosen object, using labelled arrows to represent their magnitudes and directions.

Motion in which gravity is the only force acting on an object.

The change from liquid to solid.

The number of complete wave cycles passing a fixed point each second, measured in hertz (Hz).

A force that opposes relative movement between surfaces in contact. Friction between tyres and the road provides grip during braking.

Follicle-stimulating hormone: a hormone that stimulates eggs to mature within follicles in the ovaries.

A carbon allotrope with a hollow cage-like or tubular structure.

A chemical used to kill or control fungi.

A swollen growth of plant tissue; in crown gall disease, it forms when bacteria stimulate disorganised cell growth.

A sex cell, such as an egg or sperm, containing one chromosome from each pair found in body cells.

Electromagnetic radiation emitted when a nucleus loses energy, with no change in its mass number or atomic number.

High-frequency electromagnetic radiation emitted when an atomic nucleus loses energy.

A state of matter with no fixed shape or volume; its widely spaced particles move rapidly in random directions.

Chromatography in which an unreactive carrier gas carries a vaporised sample through a column containing the stationary phase.

An instrument with a movable plunger used to collect and measure the volume of a gas.

A section of DNA carrying information, often the instructions for making a particular protein.

The different alleles present in a population.

A formula describing a family of compounds using a variable such as $n$ to represent the number of carbon atoms.

A device that transfers energy mechanically supplied by rotation into energy transferred electrically.

The use of genetic information or changes to DNA for purposes such as making medicines, testing for inherited conditions or treating disease.