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🔬 Biology  ·  Microbes in Human Welfare  ·  NEET

The genus Nucleopolyhedrovirus infects insects through which route, and what happens to infected cells?

Answer: Through ingestion of contaminated plant material, with the virus replicating in the nucleus forming polyhedral inclusion bodies that cause liquefaction of the insect.

  • A Through direct penetration of the insect skin surface, causing rapid and explosive lysis of host cells over time in standard practice under most conditions encountered
  • B Through ingestion of contaminated plant material, with the virus replicating in the nucleus forming polyhedral inclusion bodies that cause liquefaction of the insect
  • C Through entry via the respiratory tract of the insect, leading to progressive damage of the central nervous system over time as frequently observed in practice
  • D Through transovarial infection of the developing egg, causing mainly relatively minor developmental defects in many documented cases according to conventional understanding

Correct answer: B. Through ingestion of contaminated plant material, with the virus replicating in the nucleus forming polyhedral inclusion bodies that cause liquefaction of the insect

Explanation: Nucleopolyhedroviruses infect insects when larvae ingest foliage contaminated with polyhedral inclusion bodies. The virus replicates in cell nuclei, eventually causing host cell and ultimately whole-larva liquefaction (the infected caterpillar literally melts), releasing millions of viral particles.

Sewage Treatment FlowPrimaryphysical filtering+ sedimentationSecondary (aerobic)aeration tank, flocsconsume organic matterActivated sludgesettles out;part reused as inoculumSludge digesterANAEROBIC →biogas (CH₄)Note the switch: aerobic microbes in the tank, anaerobic microbes in the digester

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

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