Chapter 20, Problem 32A

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 32A

Correct answer :

The correct answer is option (c) increases the surface area of the roots

Explanation of Solution

Explanation/justification for the correct answer :

Option(c) increases the surface area of the roots. Lichen is a pioneer plant that can flourish on rocks or on small soil. Lichen also develops after natural disasters, such as fire or volcanic activity in a region of freshly cleared soil or rock. Acids formed by the lichen's fungal portion help penetrate and break down the rocks to help form the soil.So, the correct answer is option (c).

Explanation for incorrect answer :

Option (a) increases the surface area for gathering light. Lichen only requires developingwater, air, and minerals.So, this is an incorrect answer.

Options (b) decrease the need of water.Even in some of the harshest conditions, lichens can be found. Lichens consume the minerals needed from rainwater or from air dust. So, this is anincorrect answer.

Option (d)decrease the temperature.Lichen survives extreme drought. Drying out, preventing photosynthesis and becoming brittle.So, this is an incorrect answer.