Bacteria and Viruses — Prelims Strategy

Prelims Strategy

Identify whether the stem concerns cellular organisation, replication, host range or treatment. A bacteriophage question tests the difference between an agent and its host: infecting a bacterial cell does not make the virus bacterial. A prokaryote question tests the absence of a membrane-bound nucleus, not absence of genetic material or metabolism. Read those qualifiers before eliminating options.

For resistance, locate the subject of the sentence. The microorganism becomes resistant to a medicine; the patient does not become an antibiotic-resistant organism. Next check the category: antibiotic resistance concerns bacteria, whereas antimicrobial resistance is broader. An option can use a true fact about a neighbouring category and still answer the wrong question.

Use the NCERT examples carefully. Cyanobacteria show photosynthetic bacterial metabolism; viruses depend on hosts for replication. Do not convert these distinctions into claims that all bacteria cause disease or that every viral infection has the same clinical course. In application questions, distinguish a bacterial coinfection from the viral infection itself and avoid deriving treatment advice from a classification exercise.