Question

Which pigment protects plants from UV damage?
A. Chlorophyll
B. Xanthophyll
C. Phycocyanin
D. Carotenoids

Answer 1

Hint: Plant pigments are the molecules that provide different colours to different parts of the plants. Chlorophyll, carotenoids, xanthophyll, phycocyanin, porphyrins are different plant pigments known.

Complete solution
> Chlorophyll is the primary pigment of the plant that gives green colour to the leaves. It is present in plants, algae and cyanobacteria. It absorbs blue and red light in the electromagnetic spectrum. It is the main pigment that absorbs sunlight during photosynthesis. Chlorophyll is structurally made up of porphyrin ring and phytol chain with a central magnesium atom.

> Xanthophylls are yellow coloured pigments that belong to the division carotenoid. Highest quantity of xanthophyll is found in green leaves. The other rich sources of xanthophylls include papaya, peach, prunes and squash.

> Phycocyanin is an accessory plant pigment that forms a pigment-protein complex. It appears blue in colour and absorbs orange and red light. This pigment is produced by many photoautotrophic cyanobacteria.

> Carotenoids are a class of fat-soluble pigments that give yellow, orange and red colour. It gives different colours to flowers and fruits. They are produced by plants, algae, some bacteria and fungi also. It gives characteristics colour to tomatoes, carrots, pumpkins etc. They are the accessory pigments found in plants which helps in absorption of sunlight during photosynthesis.

> Carotenoids protect the plant from UV (ultraviolet) damage. They actually act as antioxidants and provide protective functions by inhibiting the UV induced free radical formation in the photosynthetic membrane.

Note: Carotenoids, xanthophylls, phycocyanin and chlorophyll are important plant pigments. Chlorophyll is the primary pigment whereas others are accessory pigments. Carotenoids participate in protecting the plants from UV damage.