Chapter 20, Problem 30A

Summary Introduction

Introduction :

Lichen is known as a symbiotic relationship between an alga or a photosynthetic host and the fungi. Usually the fungus is an ascomycete but basidiomycetes can also be found in lichens. The photosynthetic host is either a green algae or a cyanobacterium that supplies food to both animals.

Answer to Problem 30A

Correct answer :

The correct answer is option (d) It is keeping insects away.

Explanation of Solution

Explanation/justification for the correct answer :

Option(d) it is keeping insects away.Lichens consume the minerals extracted from rainwater or from air particles. The fungus absorbs rainwater so it can still consume surface moisture. Lichens are also the leader species after natural events, such as fire or volcanic activity in a region of freshly exposed soil or rock.So, the correct answer is option (d).

Explanation for incorrect answer :

Option (a) It is absorbing water.Lichens consume the minerals extracted from rainwater or from air particles. The fungus absorbs rainwater so it can still consume surface moisture.So, this is an incorrect answer.

Option (b)It is a bioindicator.Lichen as bioindicators are particularly resistant to toxins from the atmosphere, because they absorb all of their soil and rain water and minerals. A bioindicator is a living organism that is prone to changing environmental factors to respond to changing circumstances.So, this is an incorrect answer.

Option (c) It is a pioneer species. Pioneer plants are plants that can develop on poor soil or rocks. Lichens are often the pioneer species in a freshly cleared soil or rock environment after natural events, such as fire or volcanic activity. So, this is an incorrect answer.