Read the given passage and answer the following questions:

During post- industrialisation period, the tree trunks became dark due to industrial smoke and soots. Under this condition the white-winged moth did not survive due to predators, dark-winged or melanised moth survived. Before industrialisation set in, thick growth of almost white-coloured lichen covered the trees - in that background the white winged moth survived but the dark-coloured moth were picked out by predators. They will not grow in areas that are polluted. Hence, moths that were able to camouflage themselves, i.e., hide in the background, survived . This understanding is supported by the fact that in areas where industrialisation did not occur e.g., in rural areas, the count of melanic moths was low. This showed that in a mixed population, those that can better-adapt, survive and increase in population size. Remember that no variant is completely wiped out. Similarly, excess use of herbicides, pesticides, etc., has only resulted in selection of resistant varieties in a much lesser time scale. This is also true for microbes against which we employ antibiotics or drugs against eukaryotic organisms/cell. Hence, resistant organisms/cells are appearing in a time scale of months or years and not centuries. These are examples of evolution by anthropogenic action. This also tells us that evolution is not a directed process in the sense of determinism. It is a stochastic process based on chance events in nature and chance mutation in the organisms.

Which of the following can be used as an indicator of industrial pollution?

Lichens

The correct answer is Option (2) -Lichens

Lichens can be used as an indicator of industrial pollution. Lichens are sensitive to air quality, particularly to sulfur dioxide and other pollutants. In areas with high pollution, lichens either die or fail to grow, while in clean environments, they thrive. This makes them effective bioindicators for detecting pollution levels in the atmosphere.

Lichens absorb nutrients directly from the air, so they are greatly affected by air quality, making them reliable bioindicators of pollution levels.