Answer: Baculovirus.
- A Bacterium
- B Fungus
- C Baculovirus
- D Protozoan
Correct answer: C. Baculovirus
Explanation: Nucleopolyhedrovirus belongs to the group of baculoviruses, which are insect-specific viruses used as biocontrol agents.
Sewage passes through physical removal (primary), then aerobic biological treatment where microbes form flocs that consume organic matter (secondary); the settled activated sludge is then digested anaerobically to produce biogas - a deliberate switch from aerobic to anaerobic conditions between stages.
Concept context
Microorganisms in food, medicine, sewage treatment, biocontrol, and biofertilizers