Question

A colony-forming unit is the number of cells

A) that produces one colony
B) that are in exponential phase in culture
C) in a particular specimen
D) in a colony
E) that can be placed in a petri plate

Answer 1

A colony-forming unit (CFU) is a count of viable or live cells, representing the A) number of cells that can form a single colony. Two methods frequently used to estimate bacterial numbers in water samples are the pour plate and spread plate methods.

Step-by-step explanation:

A colony-forming unit (CFU) is a count of viable or live cells. It represents the number of cells that are capable of forming a single colony when incubated under suitable conditions. CFUs are usually expressed as colony-forming units per millilitre (CFU/mL) and are used to estimate the number of live cells in a sample. Two frequently used methods to estimate bacterial numbers in water samples are the pour plate and spread plate methods. In the pour plate method, serial dilutions of the sample are mixed with agar and poured into Petri dishes. In the spread plate method, the sample is spread over the surface of the agar in a petri dish. Both methods allow the counting of viable cells that give rise to colony-forming units.