In a wastewater treatment plant, which organisms primarily break down chemical and organic waste during biological treatment?

• A. Multicellular animals such as insect larvae that chemically neutralize toxins
• B. Viruses that lyse waste particles into simpler molecules
• C. Prokaryotic microorganisms (bacteria and archaea) in microbial biofilms and activated sludge
• D. Protozoa that perform photosynthesis to convert waste into sugars

Answer: (C)

Verified step by step guidance

1. Understand the role of different organisms in wastewater treatment, focusing on which types are responsible for breaking down chemical and organic waste during biological treatment.
2. Recognize that multicellular animals like insect larvae do not primarily break down chemical and organic waste; instead, they may help in physical removal or neutralization but are not the main decomposers.
3. Know that viruses do not perform decomposition of waste; they infect cells but do not chemically break down organic matter.
4. Identify that protozoa generally consume bacteria and other small particles but do not perform photosynthesis to convert waste into sugars in this context.
5. Conclude that prokaryotic microorganisms, specifically bacteria and archaea, form microbial biofilms and activated sludge, and are the primary agents that chemically break down organic and chemical waste during biological treatment.