Consider the following statements:
DNA Barcoding can be a tool to:
- 1.assess the age of a plant or animal.
- 2.distinguish among species that look alike.
- 3.identify undesirable animal or plant materials in processed foods.
Which of the statements given above is/are correct?
Answer & explanation
Answer: (d) 2 and 3
DNA barcoding identifies which species a sample belongs to by reading a short, standard piece of DNA. So it can tell apart look-alike (cryptic) species and can spot unwanted or undeclared species in processed food, but it does not tell the age of an organism.
- ✗ 1. A DNA barcode is a short standardised DNA marker used for detection and identification of species. It says what the organism is, not how old it is.
- ✓ 2. Barcodes can separate cryptic species, which look alike outwardly; a DNA mini-barcode with next-generation sequencing has been used to detect such species even in mixed seafood.
- ✓ 3. Processed foods are more likely to be substituted or adulterated with undeclared species, and DNA barcoding is used to check meat, poultry and fish products for such species.
Remember · DNA barcoding = species identification from a short standard DNA sequence (COI in animals). Uses: telling look-alike (cryptic) species apart and checking foods for undeclared species. Not for age.
Sources
- Application of DNA barcoding for ensuring food safety and quality (Food Science and Biotechnology, via US National Library of Medicine PMC) ↗ “The DNA barcoding is a detection, identification, and diagnostic technique using a short standardized DNA marker … the newly developed DNA mini-barcode combined with next-generation sequencing (NGS) can detect cryptic species in mixed raw and processed seafood … Furthermore, the processed meat products are more likely to be substituted or adulterated with undeclared species.”
Question and answer: UPSC's official GS Paper I (2022, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 1 Oct 2026 (how we verify). ·