C1.3 Photosynthesis
Photosynthesis converts light energy into chemical energy by using pigments, thylakoid reactions and Calvin-cycle carbon fixation to build organic compounds from carbon dioxide.
- Syllabus
- First assessment 2025
- Topic
- C1.3
- Level
- SL
What you’ll learn
8 learning objectivesChoose one objective for a focused lesson, or study the complete topic.
Exam analysis
An aggregate view of how the complete C1.3 Photosynthesis appears across past papers.
Chance of appearing51%of analysed past papers
Latest appearanceNovember 2025
Most common paperPaper3
Most tested objectives
- C1.3.7—Limiting factors investigation44 questions
- C1.3.4—Photosynthetic pigment separation11 questions
- C1.3.1—Light energy → chemical energy10 questions
Common question formats
- Calculation
- Comparison
- Data analysis
- Diagram interpretation
- Experimental design
- Graph interpretation
- Process explanation
- Structured response
- Definition or recall
Exam question appearances
November 2025Paper1A ["SL"] · TZ15[ 1 ]C1.3.7—Limiting factors investigation
November 2025Paper1A ["SL"] · TZ35[ 1 ]C1.3.7—Limiting factors investigation
May 2025Paper1A ["SL"] · TZ25[ 1 ]C1.3.2—CO₂ → glucose
May 2025Paper1A ["SL"] · TZ14[ 1 ]C1.3.7—Limiting factors investigation
November 2024Paper1 ["SL"] · TZ18[ 1 ]C1.3.3—Oxygen as by-product
Coverage 2010–2025 · Updated 15 Jul 2026