OCR GCSE Combined Science B key terms

Plant tissue containing stem cells that divide to supply new cells for growth, found in regions such as root and shoot tips.

A strong electrostatic attraction between positive metal ions and delocalised electrons.

The strong electrostatic attraction between positive metal ions and delocalised electrons in a metal.

Protection provided by harmless resident microorganisms that compete with pathogens.

A unit of length equal to $10^{-6}$ metres. There are 1000 micrometres in one millimetre.

Practical work carried out using very small quantities of chemicals.

An action that limits climate change by reducing greenhouse gas emissions or removing greenhouse gases from the atmosphere.

A sub-cellular structure in eukaryotic cells where many of the reactions of aerobic respiration occur.

Division of a cell’s nucleus to produce two nuclei with genetically identical sets of chromosomes.

Two or more substances together without being chemically combined with one another.

The part of a chromatography system that moves and carries dissolved substances; in paper chromatography, this is the solvent.

The value that occurs most frequently in a data set.

The amount in moles of dissolved solute per cubic decimetre of solution, measured in mol/dm³.

The mass of one mole of a substance, measured in g/mol.

The unit of amount of substance, symbol mol. One mole contains approximately $6.0\times10^{23}$ specified particles, such as atoms, molecules or formula units.

A formula giving the number of atoms of each element in one molecule, such as $\mathrm{CH_4}$.

A discrete group of atoms joined together by covalent bonds.

The product of an object's mass and velocity, measured in kg m/s. Momentum has a direction.

Existing as individual atoms rather than molecules containing two or more atoms.

The cultivation of a single crop species over an area.

A small molecule that can join with other monomer molecules to form a polymer.

The moral importance given to a being, which affects the rights and protection people believe it should have.

Deaths in a population, often expressed as a rate over a stated period.

The force-producing interaction between the magnetic field of a current-carrying conductor and an external magnetic field.

A neurone that carries electrical impulses from the central nervous system to an effector.

A number used to multiply an original amount to obtain a new amount. For example, a multiplier of 1.20 increases an amount by 20%.

A change in DNA that can produce a new genetic variant.