Question

Which of the following are most suitable indicators of SO2 pollution in the environment?

• A. Algae
• B. Fungi
• C. Lichens
• D. Conifers

Answer 1

The Correct Option is C

To determine the most suitable indicators for sulfur dioxide (SO₂) pollution in the environment, we need to understand the sensitivity of different organisms to air pollutants.

Lichens are known to be the most reliable indicators of air quality and pollution levels. Here's why:

1. Biological Characteristics: Lichens are a symbiotic relationship between fungi and algae or cyanobacteria. They lack roots and absorb nutrients directly from the air.
2. Sensitivity to Pollutants: They are particularly sensitive to air pollution due to their dependence on atmospheric nutrients. SO₂ can inhibit photosynthesis in lichens, making them highly sensitive to sulfur dioxide pollution.
3. Absence of Protective Structures: Lichens lack a cuticle, the protective layer found in plants, which makes them more susceptible to air pollutants, including SO₂.
4. Indicators of Air Quality: Lichens are among the first organisms to respond to changes in air quality, providing visible and measurable shifts in species abundance, composition, and health.

Given these factors, lichens are extensively used as bioindicators for monitoring SO₂ pollution.

Now, let's rule out other options:

• Algae: While some aquatic algae can be indicators of water quality, they are not the primary choice for air pollution indicators, especially SO₂.
• Fungi: Fungi in general are not used as primary indicators of air pollution. They can be affected by air quality but are not as directly indicative of SO₂ levels as lichens.
• Conifers: These are resilient trees that can show some response to air pollution, but they are not as sensitive or directly indicative of SO₂ pollution as lichens.

In conclusion, the correct answer is Lichens because they are the most sensitive and reliable indicators of sulfur dioxide (SO₂) pollution in the environment.