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C3.1.23 (HL)—Ethylene and fruit ripening

Ethylene and fruit ripening links named stimuli, coordinating structures and effectors so body systems or plant tissues produce an integrated biological response.

Syllabus
First assessment 2025
Objective
C3.1.23
Level
HL

Exam analysis

Chance of appearing2%of analysed past papers
Latest appearanceMay 2025
Most common paperPaper1A
Typical marks1

Common command terms

  • Identify

Scoring notes

Common mistake
Treating low oxygen as the only trigger and omitting carbon-dioxide-driven pH change.

Recent exam appearances

May 2025Paper1A ["HL"] · TZ128[ 1 ]C3.1.23 (HL)—Ethylene and fruit ripening
May 2025Paper1A ["HL"] · TZ226[ 1 ]C3.1.23 (HL)—Ethylene and fruit ripening
Practice this objective

Coverage 2025–2025 · Updated 16 Jul 2026

Concept essentials

  • Ethylene and fruit ripening depends on linking the stimulus to the coordinating structure or signal.
  • The pathway for ethylene and fruit ripening must keep information flow and response direction clear.
  • Named tissues, hormones, neurons or effectors give ethylene and fruit ripening its biological specificity.
  • Evidence about ethylene and fruit ripening is strongest when structure, mechanism and outcome are connected.
ConceptIB Biology HL