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?

The correct answer is 2 and 3.

Key Points

• DNA barcoding is a technique used to identify species based on short, standardized regions of DNA (like the COI gene for animals and rbcL or matK genes for plants).
  • ​It does not provide information about the age of an organism. The process focuses on species identification, not on individual characteristics such as age. Hence, 1 is incorrect.
  • Carbon dating is a technique used to determine the approximate age of once-living materials. It is based on the decay rate of the radioactive carbon isotope C14, a form of carbon taken in by all living organisms while they are alive.
• One of the main uses of DNA barcoding is to distinguish species that may look very similar morphologically but are genetically different.
  • This technique helps in identifying species that are otherwise hard to distinguish based on physical traits alone (e.g., cryptic species).
  • For example, different species of butterflies or plants that look almost identical can be distinguished by their DNA barcode. Hence, 2 is correct.
• DNA barcoding can be used in food safety and quality control to identify the presence of specific plant or animal materials in processed foods.
  • This can be useful to detect contamination, mislabeling, or the inclusion of undeclared ingredients (e.g., detecting horse meat in beef products or identifying allergens).
  • DNA barcoding has become a valuable tool in ensuring food authenticity and safetySafety assessment of food. Hence, 3 is correct.

Additional Information

DNA barcoding

• It is a methodology for rapidly and accurately identifying species by sequencing a short segment of standardized gene regions and comparing individual sequences to a reference database.
• Some applications of DNA barcoding include:
  • Identiication of new species 
  • Detection of alien/invasive species
  • Identification of endangered and threatened species
  • Linking egg and larval stages to adult species
  • Securing intellectual property rights for bioresources
  • Framing global management plans for conservation strategies
  • Identifying plant leaves even when flowers or fruits are not available
  • Identifying pollen collected on the bodies of pollinating animals.