IGCSE Biology glossary
Chlorophyll
Biology editorial review is supported by the named review panel. Reviewer participation may vary by guide. Checked against Cambridge IGCSE Biology 0610 (2026–2028); last reviewed August 2026.
Definition
The green pigment found in chloroplasts that absorbs light energy for photosynthesis. Chlorophyll absorbs red and blue wavelengths of light most effectively and reflects green light, which is why leaves appear green.
What to include in an exam answer
State that chlorophyll 'absorbs light energy' rather than 'takes in sunlight'. In variegated leaf experiments, only green parts (with chlorophyll) produce starch, proving chlorophyll is needed for photosynthesis.
Example in context
Explain why a variegated leaf only turns blue-black with iodine solution in the green areas (3 marks): Only the green areas contain chlorophyll. Chlorophyll absorbs light energy needed for photosynthesis. Only these areas produce glucose, which is stored as starch, which turns iodine solution blue-black.
Related syllabus topic
Plant nutrition