Question

Sol.(b) [Key Concept: Lichens — Atmospheric Pollution Indicators] Lichens can be used as atmospheric pollution indicators. As they are sensitive (especially phycobiont) to oxides of nitrogen and sulphur, they do not grow in polluted areas — they are unable to synthesise organic food and do not grow well. Their absence indicates pollution; luxuriant growth indicates clean air. Lepidoptera = insect order; Lycopersicon = tomato; Lycopodium = pteridophyte.