Question

Which one of the following is not true for lichens?

• A. They can be used to produce litmus.
• B. Some species can be used as pollution indicators.
• C. They can grow very fast.
• D. Their body is composed of both algae and fungal components.

Answer 1

The correct option is C They can grow very fast.

Lichens are formed by the symbiotic association between algae and fungi and have a unique morphology distinct from both partners. Litmus is a blue dye extracted from various species of lichens especially Rocella tinctoria. Lichens are very sensitive to sulphur dioxide pollution in the air. If air is very badly polluted with sulphur dioxide there may be no lichens present. They are sensitive to sulphur dioxide, because their efficient absorption systems result in rapid accumulation of sulphur when exposed to high levels of sulphur dioxide pollution. The growth rate of lichen is very slow even less than a millimeter per year and this property is used to determine the age of exposed rock.

So, the correct answer is option C.