The special pigment for colour change in chameleon is

1. Analyze the question The question asks which structure or pigment is responsible for colour change in the chameleon.

2. Explain the concept Chameleons change colour using special pigment-containing cells in the skin called chromatophores. These cells hold pigment granules, and the pigment can spread out or clump together inside the cell. This changes how light is reflected, so the animal's skin colour changes. Mood, temperature, light and the surroundings can all trigger the change.

3. Go through the options

• A. Melanin: This is a dark pigment found in many animals, including humans. It is one of the pigments inside chromatophores, but it is not the special colour-changing structure by itself.
• B. Carotenoid: This is a yellow-orange-red pigment from plants and the diet. It is not the colour-change mechanism.
• C. Chromatin: This is the DNA-protein material in the nucleus. It has nothing to do with colour.
• D. Chromatophore: This is the pigment-bearing cell responsible for colour change in chameleons, and in some fish and amphibians too.

4. Answer The correct option is D. chromatophore.

5. Exam tip Break the word down. "Chroma" means colour and "phore" means bearer, so chromatophore means "colour-bearer". Don't confuse it with chromatin (nucleus material) or chromosome (carries genes).