Question

Lichen indicate

• A. air pollution due to its sensitivity to $CO.$
• B. air pollution due to its sensitivity to SO₂.
• C. pollution due to smoke.
• D. noise pollution.

Answer 1

Answer: (B)

Lichens are a symbiotic association of the algae (phycobiont) and fungi (mycobiont). The algal partner produces food and the fungal partner provides protection to the algae. The fungi also help in absorption of minerals and water. Lichens generally do not grow in polluted areas, hence they are good indicators of pollution due $S{O}_2$ . Air pollutants dissolved in rainwater, especially $S{O}_2$ (sulphur dioxide) can damage lichens.