CFU is a unit used to quantify what kind of biological material?

• A. Colony forming units
• B. Certified fermentation units
• C. Certified food units
• D. Colony fluorescent units

Answer: (A)

CFU measures the number of viable microorganisms that can grow into colonies on culture media. In practice, a sample is plated, and each live organism that can reproduce forms a visible colony. Counting these colonies gives an estimate of how many live cells were present originally, which is why CFU is described as colony forming units. This focuses on living, replicating cells, not dead cells or other properties like fluorescence. That’s why the option describing Colony Forming Units is the best answer, while the others don’t represent a standard unit used to quantify viable microbes.