The minimum requirement for an ecosystem to recycle nutrients present in it would be:
1. | producers |
2. | producers and decomposers |
3. | producers, primary consumers, and decomposers |
4. | producers, primary consumers, secondary consumers, and decomposers |
Which of the following is not a correct difference between a grazing food chain [GFC] and a detritus food chain [DFC]?
|
GFC |
DFC |
1. |
Major conduit of energy flow in aquatic ecosystem |
Major conduit of energy flow in terrestrial ecosystem |
2. |
Much larger energy flows through it |
Much smaller energy flows through it |
3. |
Begins with producers |
Begins with dead organic matter |
4. |
Energy for this food chain comes from the sun |
Energy for this food chain comes from the remains of detritus |
Assertion (A): | There is no limitation on the number of trophic levels in a detritus food chain. |
Reason (R): | The transfer of energy between successive trophic levels in a detritus food chain does not follow the 10% rule. |
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. |
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The nutrients in an ecosystem are:
1. | continuously lost from an ecosystem |
2. | needed as a continuous supply from the outside |
3. | recycled time and again indefinitely |
4. | continuously synthesized by physical forces |
Given below is a hypothetical pyramid of energy. The amount of energy left at the level of secondary consumers would approximately be:
1. | 10000 J | 2. | 1000 J |
3. | 100 J | 4. | 50 J |
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Identify the incorrectly matched pair:
1. |
Vertical distribution of different species occupying different levels |
Stratification |
2. |
Mass of living material at a particular time at each trophic level |
Standing crop |
3. |
Rate of formation of new organic matter by consumers |
Net primary productivity |
4. |
The rate of production of organic matter during photosynthesis |
Gross primary productivity |
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Assertion (A): | Most of an ecosystem’s production is eventually consumed by detritivores and decomposers. |
Reason (R): | Energy is said to flow through, not cycle within, ecosystems. |
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. |
An inverted pyramid of biomass can be found in which ecosystem?
1. | Forest | 2. | Marine |
3. | Grassland | 4. | Tundra |
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Consider the following statements:
The rate of decomposition is high if:
I: | The detritus is rich in lignin and chitin. |
II: | The detritus is rich in nitrogen and sugars. |
III: | The environmental conditions are warm and moist. |
Which of the above statements are true?
1. | I and II only | 2. | I and III only |
3. | II and III only | 4. | I, II, and III |
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Converting nitrate to nitrogen gas by anaerobes like Pseudomonas is:
1. | nitrogen fixation | 2. | ammonification |
3. | denitrification | 4. | eutrophication |