- A To culture and grow visible bacterial colonies on nutrient agar plates over several days
- B To detect specific DNA or RNA sequences of pathogens with high sensitivity and specificity
- C To directly measure the circulating antibody concentration present in a blood serum sample
- D To propagate and amplify whole viruses inside living host cell cultures over time
Correct answer: B. To detect specific DNA or RNA sequences of pathogens with high sensitivity and specificity
Explanation: PCR (Polymerase Chain Reaction) amplifies specific DNA/RNA sequences for detection. Used to diagnose: HIV (viral load), TB (detect M. tuberculosis DNA), COVID-19, dengue. It is highly sensitive and can detect even tiny amounts of pathogen genetic material.
Concept context
Pathogens, infectious diseases, non-infectious diseases, drugs, cancer, and public health. High NEET importance.