Question

Organisms which are indicator of SO pollution of air

• A. mosses
• B. lichens
• C. mushrooms
• D. puffballs.

Answer 1

The Correct Option is B

To determine which organisms act as indicators of sulfur dioxide (SO₂) pollution in the air, we need to understand their sensitivity and role in the ecosystem.

Lichens are known as sensitive bioindicators of air quality, particularly for sulfur dioxide (SO₂). They are a symbiotic relationship between a fungus and an alga or cyanobacterium. The absence or reduced presence of lichens in polluted environments is often a sign of high levels of air pollutants including sulfur dioxide.

Let's explore the options to justify why lichens are the correct choice:

1. Mosses: While mosses can be used as bioindicators, they are generally less sensitive to air pollution than lichens and are not the primary indicators for sulfur dioxide.
2. Lichens: As mentioned, lichens are highly sensitive to air pollution, especially to sulfur dioxide. They can absorb water and nutrients from the air and thus directly reflect air quality changes. Due to their sensitivity, lichens disappear from areas with high SO₂ concentrations.
3. Mushrooms: Mushrooms primarily grow in soil and play a different ecological role; they are not commonly used as air pollution indicators.
4. Puffballs: Like mushrooms, puffballs are fungi that primarily grow on the ground and are not specific indicators of sulfur dioxide pollution.

Thus, lichens are the most suitable organisms for indicating SO₂ pollution in the air due to their high sensitivity.