The growth of lichens on trees indicates the level of pollution in the surrounding environment. The correct answer is option 'D', which states that the location is not polluted.

Explanation:

Lichens are composite organisms that consist of a fungus and a photosynthetic partner, either an alga or a cyanobacterium. They are sensitive to environmental changes, especially air pollution. Here are some possible reasons why the growth of lichens on trees can indicate the level of pollution in the surrounding environment:

Lichens are bioindicators of air quality:

• Lichens absorb nutrients, water, and gases from the environment through their thallus (body), which is exposed to the air.

• Lichens are capable of accumulating heavy metals, radionuclides, and other pollutants from the air and rainwater.

• Lichens are sensitive to sulfur dioxide (SO2), nitrogen oxides (NOx), ozone (O3), and particulate matter (PM) in the air.

Lichens respond to pollution in different ways:

• Some lichens are more tolerant to pollution than others, depending on their species and genetic diversity.

• Some lichens grow faster in polluted environments, while others grow slower or die off.

• Some lichens change color or shape in response to pollution, such as turning black, brown, or shriveled.

Lichens indicate the quality of habitat:

• Lichens form a symbiotic relationship with trees, rocks, soil, and other substrates.

• Lichens require a certain level of moisture, light, and nutrients to survive and grow.

• Lichens can indicate the health of trees by showing the presence or absence of bark damage, insect infestation, or other stressors.

Conclusion:

In summary, a location with the luxuriant growth of lichens on the trees indicates that the location is not polluted. The presence of lichens on trees is a good sign of a healthy environment. However, the absence of lichens does not necessarily mean that the location is polluted, as there could be other factors that affect their growth. Therefore, lichens should be used in combination with other bioindicators, such as mosses, fungi, and insects, to assess the quality of the habitat.

Lichena r the best pollution indicators... They never grows in polluted areas..

Lichens r the symbiotic association between algae n fungi...