Answer: Cry proteins encoded by cry genes.
- A Flagellar proteins used for bacterial movement
- B Cry proteins encoded by cry genes
- C Capsular polysaccharides forming a protective layer
- D Endospore coat proteins protecting the dormant spore
Correct answer: B. Cry proteins encoded by cry genes
Explanation: Cry proteins (also called delta endotoxins or crystalline proteins) encoded by cry genes are the insecticidal components of Bacillus thuringiensis that kill caterpillars and other insect larvae.
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