Question

On his walk to the nearest park, Rahul saw lichens growing on the trees. What can he infer from this observation?

• A. The neighbourhood has high levels of pollutants in the soil
• B. The level of air pollution is very high in the neighbourhood
• C. The air in the neighbourhood is not polluted
• D. The water sources in the neighbourhood are polluted

Answer 1

The correct option is C The air in the neighbourhood is not polluted

Lichens are symbiotic associations between a fungal component (mycobiont) and an algal component (phycobiont). The alga is the photosynthetic producer which prepares food for itself and the heterotrophic fungal component. The fungal component provides shelter to the algal component and also absorbs water and minerals for it to prepare food.

Lichens are important pollution indicators because they do not grow in areas which have air pollution. So, the growth of lichens indicates that the level of pollution in the area is very less.

Thus, option c is correct.

Lichens are not indicators of water and soil pollution as they usually grow on rocks and trees.