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.
- A.1 and 4 only
- B.2 only
- C.2 and 3
- D.1, 3 and 4
Correct answer
Explanation
The correct answer is C, 2 and 3. Lichens and mosses can live on bare rock, tree bark and walls without any soil, and they are the pioneer species of primary succession.
A lichen is a partnership of a fungus and an alga or cyanobacterium: the alga makes food by photosynthesis while the fungus holds water and grips the surface. Lichens release acids that slowly break rock, and their dead remains begin to form a thin layer of soil. Mosses, which have rhizoids instead of true roots and absorb water over their whole surface, then settle in these cracks and add more organic matter. Only after this do ferns, grasses and larger plants arrive.
A is wrong: ferns need soil for their roots, and mushrooms feed on decaying organic matter in soil or wood.
B is wrong: it leaves out moss, which also grows on bare rock.
D is wrong: it includes fern and mushroom, which depend on soil or dead organic matter.
Exam tip: primary succession on bare rock = lichens first, then mosses, then ferns and grasses.
Practice Questions
View allA biological community in its environment such as a pond, an ocean, a forest, even an aquarium is known as
- A.biome
- B.community
- C.abiotic environment
- D.ecosystem
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An ecosystem is a community of living things together with the non-living environment they interact with, and it can be as large as an ocean or as small as an aquarium.
Read the full explanation →Consider the following statements :
I. Carbon dioxide (CO2) emissions in India are less than 0.5 t CO2/capita.
II. In terms of CO2 emissions from fuel combustion, India ranks second in Asia-Pacific region.
III. Electricity and heat producers are the largest sources of CO2 emissions in India.
Which of the statements given above is/are correct?
- A.I and III only
- B.II only
- C.II and III only
- D.I, II and III
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Read the full explanation →The term 'Domestic Content Requirement' is sometimes seen in the news with reference to
- A.Developing solar power production in our country
- B.Granting licences to foreign T.V. channels in our country
- C.Exporting our food products to other countries
- D.Permitting foreign educational institutions to set up their campuses in our country
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Read the full explanation →In the context of which of the following do some scientists suggest the use of cirrus cloud thinning technique and the injection of sulphate aerosol into stratosphere?
- A.Creating the artificial rains in some regions
- B.Reducing the frequency and intensity of tropical cyclones
- C.Reducing the adverse effects of solar wind on the Earth
- D.Reducing the global warming
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Read the full explanation →Which of the following have species that can establish symbiotic relationship with other organisms?
1. Cnidarians
2. Fungi
3. Protozoa
Select the correct answer using the code given below.
- A.1 and 2 only
- B.2 and 3 only
- C.1 and 3 only
- D.1, 2 and 3
Show answer
Cnidarians, fungi and protozoa all include species that live in close, mutually useful partnerships with other organisms. Symbiosis means two different species living closely together, often to the benefit of both.
Read the full explanation →