5 of the Biology glossary’s terms, each with the part of the syllabus where you first meet it.
A square frame of known area used to mark out a sample area so that the organisms inside it can be counted or their percentage cover estimated.
Observations described in words rather than measured, for example the colour, shape or texture of cells seen with a microscope.
Observations recorded as numbers with units, obtained by measuring or counting, for example the length of a cell in micrometres.
The arrangement of two or more polypeptide subunits, and of any non-polypeptide prosthetic groups, in a protein.
A form of cell signalling in which bacteria release autoinducer molecules and change their gene expression when the autoinducer concentration, and therefore the population density, rises above a threshold.