Edexcel GCSE Combined Science key terms

A region of plant tissue containing unspecialised cells that divide by mitosis and can give rise to specialised plant cells.

The chemical reactions that take place within a living organism.

An ionic compound containing positive metal ions and negative halide ions.

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

A unit of length equal to $10^{-6}$ metres. Its symbol is µm.

A unit of length equal to $10^{-3}$ metres. Its symbol is mm.

Action that reduces the causes of climate change, for example by reducing greenhouse gas emissions.

An organelle where aerobic respiration reactions take place, releasing energy for cell activities.

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

Two or more substances physically mixed together, rather than chemically combined with one another. Each substance retains its chemical properties.

The moving solvent that carries dissolved substances through the stationary phase during chromatography.

The mass of one mole of a substance, measured in g mol⁻¹. Its numerical value equals the appropriate relative particle mass.

The unit of amount of substance, symbol mol. One mole contains $6.02 \times 10^{23}$ specified particles.

A formula showing the actual number of atoms of each element in one molecule.

A group of atoms held together by covalent bonds.

The product of an object’s mass and velocity: $p = mv$. Momentum is a vector quantity, measured in kilogram metres per second (kg m/s).

Existing as separate single atoms rather than molecules.

The inheritance of a characteristic controlled by a single gene.

The force on a current-carrying conductor in a magnetic field, caused by the interaction between the conductor’s magnetic field and the external magnetic field.

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

A sticky substance that traps pathogens in the nose and airways.

An organism made of more than one cell.

A change in DNA, the genetic material in a cell.

A relationship between two species in which both benefit.

A fatty insulating layer around a nerve fibre that speeds up electrical impulse transmission.

A unit of length equal to $10^{-9}$ metres. Its symbol is nm.

The network of cables and transformers that transfers electrical energy from power stations to consumers.

A metal found naturally as an uncombined element rather than chemically combined in a compound.