UPSC Prelims 2021 Question:

In the nature, which of the following is/are most likely to be found surviving on a surface without soil?

1. Fern 
2. Lichen 
3. Moss 
4. Mushroom
   

Select the correct answer using the code given below.

Explanation:

• The ferns are most commonly plants of shaded damp forests of both temperate and tropical zones. Some fern species grow equally well on soil and on rocks. Ferns require indirect sunlight, moist soil, and a humid atmosphere. Ferns prefer potting soil with good drainage and high organic content. So, point 1 is not correct.
  
  
• Lichens have specific requirements for their habitats. Although they can occur on a variety of substrates, each substrate must have the individual components in the right amounts that growing lichen needs. These requirements are water, air, nutrients, light, and substrates. So, point 2 is correct.
  
  
• Moss: A moss is a flowerless, spore-producing plant - with the spores produced in small capsules. The plant often grows from trees, absorbing water and nutrients from the atmosphere. So, point 3 is correct.
  
  
• A mushroom, or toadstool, is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground on soil or on its food source. So, point 4 is not correct.
  
  

Therefore, option (3) is the correct answer.

Subject: Environment | Ecology