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A3.1.15 (HL)—Environmental DNA barcodes

DNA barcoding identifies species using short diagnostic DNA sequences, including sequences recovered from environmental DNA samples in habitats and ecosystems.

Syllabus
First assessment 2025
Objective
A3.1.15
Level
HL

Exam analysis

Chance of appearing1%of analysed past papers
Latest appearanceMay 2025
Most common paperPaper1A
Typical marks1

Recent exam appearances

May 2025Paper1A ["HL"] · TZ322[ 1 ]A3.1.15 (HL)—Environmental DNA barcodes
Practice this objective

Coverage 2025–2025 · Updated 15 Jul 2026

Concept essentials

  • DNA barcodes are short diagnostic sequences used for species identification.
  • Environmental DNA can reveal organisms present in a habitat.
  • PCR and database comparison are central to barcode-based identification.
  • DNA barcoding is different from sequencing an entire genome.
ConceptIB Biology HL