Detailed Explanation:

Answer: Option 4 — 2 and 3

DNA barcoding is a molecular technique that uses short, standardized gene sequences to identify species. It is particularly effective for distinguishing morphologically similar species and detecting species composition in processed materials, but it cannot determine the age of organisms.

❌ Statement 1 – Incorrect: DNA barcoding identifies species based on genetic sequences but cannot assess the age of a plant or animal, as age determination requires other methods like dendrochronology or carbon dating.

✅ Statement 2 – Correct: DNA barcoding excels at distinguishing among species that look morphologically similar by comparing their unique genetic barcodes (typically COI gene in animals, rbcL or matK in plants).

✅ Statement 3 – Correct: DNA barcoding is extensively used in food safety to identify undeclared or undesirable animal/plant materials in processed foods, helping detect food adulteration and mislabeling.

📝 Short Notes: DNA Barcoding

• Definition: A molecular tool that uses short, standardized DNA sequences to rapidly identify species
• Gene Markers: COI (Cytochrome C Oxidase I) for animals; rbcL, matK, ITS for plants
• Applications: Species identification, biodiversity assessment, food authentication, detection of illegal wildlife trade, identification of medicinal plants
• Advantages: Works with small tissue samples, identifies cryptic species, useful for immature/damaged specimens
• Limitations: Cannot determine age, recent speciation may show similar sequences, requires reference database
• Global Initiative: International Barcode of Life (iBOL) project maintains comprehensive DNA barcode libraries