How are new cells produced in the activated sludge process?

• A. Synthesis
• B. Division
• C. Budding
• D. Mitosis

Answer: (A)

In the activated sludge process, new cells arise from synthesis of cellular components using the nutrients in the wastewater. Microorganisms take in organic matter and build up proteins, nucleic acids, lipids, and other components, increasing their biomass. When enough material has been synthesized, the cells then divide to form new cells. Mitosis is a process that occurs in certain eukaryotic cells and isn’t how bacteria in sludge reproduce, and budding isn’t the typical mode for these microbes. So the production of new cells is best described by synthesis.