Q. Consider the following statements regarding “lichens”:
1.It is a combination of an alga and bacteria.
2.They are found in rivers and ground water.
Which of the statements given above is/are correct?

[A] 1 only

[B] 2 only

[C] Both 1 and 2

[D] Neither 1 nor 2

Answer: D

Explanation: A lichen is a peculiar combination of an alga and a fungus– the two live deriving mutual benefit.

  • They are group of greyish green plants which grow on rocks, tree-trunks, dead wood, etc.
  • The algae manufacture food which becomes available to the fungus, and the absorbs and retains water and thus keeps the algal cells moist. A example of symbiosis.
  • They are most common in wetlands, rare in rivers and streams and are not found in ground water.

Source: Shankar IAS Environment book