Answer: Detect very low amounts of pathogen early by amplifying DNA or detecting antigens.
- A Detect very low amounts of pathogen early by amplifying DNA or detecting antigens
- B Detect the disease only after obvious clinical symptoms have already appeared
- C Work only for bacterial diseases
- D Replace the need for any treatment
Correct answer: A. Detect very low amounts of pathogen early by amplifying DNA or detecting antigens
Explanation: PCR amplifies even a few copies of pathogen DNA and ELISA detects antigens or antibodies, so infections can be detected very early, before the pathogen builds up to symptomatic levels.
Concept context
GM crops, transgenic animals, gene therapy, molecular diagnostics, and bioethics. Frequent 2–3 mark questions in NEET.