OCR GCSE Combined Science B key terms

Taking samples at predetermined regular intervals, for example along a transect.

A straight line with the same direction as a curve at a particular point. Its gradient estimates the curve’s rate of change there.

Setting a balance to zero with an empty container on it, so that the subsequent reading gives the mass of its contents.

A cell with a suitable receptor for a particular hormone, allowing it to respond to that hormone.

The loss of a metal's shiny appearance as a dull surface coating forms through reaction with its surroundings.

The branch of biology concerned with classifying and naming organisms.

The application of scientific knowledge to develop useful products, processes or systems.

The difference between the final and initial temperatures: $\Delta T = T_{\text{final}} - T_{\text{initial}}$.

A material’s ability to resist being pulled apart.

An arrangement in which an atom has four bonded neighbours directed towards the corners of a tetrahedron.

The maximum calculated mass of product obtainable from the available reactants, assuming complete reaction.

A property describing how readily a material transfers energy by conduction. Higher thermal conductivity means faster transfer under otherwise identical conditions.

Energy stored by particles in a substance. Heating an object normally increases its thermal energy store.

A material or arrangement that reduces the rate of energy transfer by heating.

Electromagnetic radiation emitted by an object because of its temperature.

A temperature-sensitive resistor. In the type studied here, resistance decreases as temperature increases.

A polymer with covalent cross-links forming a network that does not soften or melt on heating.

A polymer that softens on heating and can be reshaped because its chains can move past one another.

The distance a vehicle travels during the driver's reaction time, before braking begins.

A hormone released by the pituitary gland that stimulates the thyroid gland to release thyroxine.

A hormone released by the thyroid gland that stimulates basal metabolic rate.

A group of cells working together to carry out a particular function.

A method of measuring the volume of one solution needed to react exactly with a measured volume of another solution.

The volume delivered from a burette during a titration, calculated as final reading minus initial reading.

The ability of a substance to cause harmful effects.

A poisonous substance that can damage cells or interfere with their normal function.

A line across a habitat along which organisms or environmental conditions are sampled.