Bacterial Growth Curve - GCSE Biology Definition

The bacterial growth curve is a graphical representation that shows the stages of growth of a bacterial population over time under controlled conditions. In GCSE Biology, students learn that that this curve typically consists of four distinct phases:

• Lag phase, where bacteria adjust to their new environment but do not divide rapidly;

• Log (exponential) phase, where bacteria reproduce quickly and the population grows rapidly;

• Stationary phase, where growth slows as nutrients become limited and waste builds up, so the rate of cell division equals the rate of cell death;

• Death phase, where the number of dying cells exceeds the number of new cells due to exhausted resources and toxic waste.

This curve illustrates how bacterial populations expand and respond to changes in their environment.