State, giving one specific example, how individual bacteria change their characteristics when they form aggregates.

example;
change;
e.g.:
Vibrio fischeri;
emit light when part of high density population/high concentration of regulatory substance;
Accept other verifiable example.

The majority of candidates exhibited knowledge and gained marks in part (a), but some failed to gain all of them because of imprecision in their answers; a certain number of candidates, especially in French scripts, confused between the type of clusters characteristic of certain bacteria seen under the microscope (e.g. grape-like clusters in Staphylococcus sp.), and aggregates causing a change in properties.