Identify the correct statements: 

I: Only a few individuals can be taken into account at any trophic level and the deductions may be generalised.
II: Trophic level is a functional level and does not represent a species.
III:  A given species may occupy more than one trophic level in the same ecosystem at the same time.
 
1. Only I and II 2. Only I and III
3. Only II and III 4. I, II, III and IV
Subtopic:  Ecological Pyramids |
 63%
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The given figure shows pyramid of numbers in a grassland ecosystem. What will be be true for pyramid of numbers?
 
 
I:  A pyramid of numbers shows graphically the population, or abundance, in terms of the number of individual organisms involved at each level in a food chain. 
II:  The pyramid shows the number of organisms in each trophic level and it does not consider individual sizes or biomass. 
III:  It is not necessary that the pyramid is always upright. For example, it will be inverted if beetles are feeding from the output of forest trees, or parasites are feeding on large host animals.
 
1. Only I and II
2. Only I and III
3. Only II and III
4. I, II and III
Subtopic:  Ecological Pyramids |
 77%

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Pyramid of numbers is :
1. Always upright
2. Always inverted
3. Either upright or inverted
4. Neither upright nor inverted

Subtopic:  Ecological Pyramids |
 84%
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The given pyramid of biomass shows a sharp decrease in biomass at higher trophic levels. What can be the reason for this sharp decrease? 
 
 
I:  The respiration cost increases sharply along successive higher trophic levels.
II:  There can be lower amounts of biomass at the bottom of the pyramid if the rate of primary production per unit biomass is high.
 
1. Both I and II are correct and II explains I.
2. Both I and II are correct but II does not explain I.
3. I is correct but II is incorrect.
4. I is incorrect but II is correct.
Subtopic:  Ecological Pyramids |

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Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Some aquatic ecosystems have inverted biomass pyramids.
Reason (R): The pyramid of energy is also inverted in such ecosystems.
In the light of the above statements, choose the most appropriate answer from the options given below :
1. Both (A) and (R) are True and (R) is the correct explanation of (A).
2. Both (A) and (R) are True but (R) is not the correct explanation of (A).
3. (A) is True but (R) is False.
4. Both (A) and (R) are False.
Subtopic:  Ecological Pyramids |
 83%
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The figure shows an inverted pyramid of biomass. What will be true for such a pyramid? 
 
I: An example of such a pyramid will be the pyramid of biomass in a pond ecosystem, where the standing crop of phytoplankton, the major producers, at any given point will be lower than the mass of the heterotrophs.
II:  The phytoplankton reproduce very quickly, but have much shorter individual lives.
 
1. Both I and II are correct and II explains I.
2. Both I and II are correct but II does not explain I.
3. I is correct but II is incorrect.
4. I is incorrect but II is correct.
Subtopic:  Ecological Pyramids |
 72%

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The ecological pyramids that can never be inverted in a natural ecosystem include:

I:  pyramid of numbers
II:  pyramid of energy in any ecosystem
III:  pyramid of biomass in the sea

1. Only II
2. Only III
3. Only II and III
4. All can be inverted

Subtopic:  Ecological Pyramids |
 84%
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Study the representation of an ideal pyramid of energy in the given figure. Which of the following will be true regarding this pyramid?
 
 
1. The rate of production over a period of time is not taken into account.
2. Two species of comparable biomass may have very different life spans. Thus, a direct comparison of their total biomasses is misleading, but their productivity is directly comparable.
3. The relative energy chain within an ecosystem cannot be compared using pyramids of energy; also different ecosystems cannot be compared.
4. It can be inverted in certain ecosystems.
Subtopic:  Ecological Pyramids |
 63%

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In an open ocean, the pyramid of biomass is often inverted. How can this support higher trophic levels?

1.  The food produced by primary producers is of high quality
2.  The primary producers grow and reproduce at high rates
3.  Primary producers are very abundant.
4.  The predators at higher trophic levels are very efficient
Subtopic:  Ecological Pyramids |
 57%
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