The greatest diversity of animal and plant species is found in :
- A.Temperate forests
- B.Deserts and Savannas
- C.Arctic and Alpine systems
- D.Tropical moist forests
Correct answer
Explanation
The correct answer is D, Tropical moist forests. Tropical rainforests hold more plant and animal species than any other land ecosystem.
These forests cover only about six to seven per cent of the Earth's land, yet they are thought to hold more than half of all known land species. Steady warmth, heavy rain all year and strong sunlight keep plants growing without a break, and the many layers of the forest, from the floor to the emergent canopy, create a huge number of niches. The Amazon basin, the Congo basin, Southeast Asia, and in India the Western Ghats and the North-East are examples. Species richness generally rises from the poles towards the equator.
A is wrong: temperate forests have cold winters and a shorter growing season, so they hold far fewer species.
B is wrong: deserts and savannas are limited by low or seasonal rainfall.
C is wrong: Arctic and alpine systems are cold, with short summers, and have the lowest diversity of the four.
Exam tip: biodiversity increases from the poles to the equator; tropical rainforests are the richest land biome.
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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India is the second-largest emitter of fuel-combustion CO2 in the Asia-Pacific after China, and power and heat generation is its biggest source, but its per capita emissions are well above 0.5 tonne.
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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Domestic Content Requirement (DCR) is the rule that certain solar projects must use solar cells and modules made in India.
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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Both ideas are geoengineering proposals meant to cool the planet by changing how much heat enters or leaves the Earth.
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
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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.
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