Q. No.Stratification of an ecosystem means:
| 1. | Vertical distribution of different species occupying different levels |
| 2. | Vertical distribution of different species occupying the same levels |
| 3. | Horizontal distribution of different species occupying different levels |
| 4. | Horizontal distribution of different species occupying the same levels |
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 |
Unlike terrestrial ecosystems, the majority of primary production in the ocean is:
| 1. | not dependent on the Sun as the source of energy |
| 2. | performed by phytoplankton |
| 3. | not limited by the availability of nitrogen |
| 4. | not important from a global perspective |
Secondary productivity in an ecosystem can be defined as:
| 1. | The amount of chemical energy, typically expressed as carbon biomass, that primary producers create in a given length of time. |
| 2. | The rate at which all the autotrophs in an ecosystem produce net useful chemical energy. |
| 3. | The rate of formation of new organic matter by consumers. |
| 4. | The amount of energy released by the action of detritivores and decomposers in an ecosystem. |
Which of the following correctly describes the secondary productivity in an ecosystem?
| 1. | The amount of chemical energy, typically expressed as carbon biomass, that primary producers create in a given length of time. |
| 2. | The rate at which all the autotrophs in an ecosystem produce net useful chemical energy. |
| 3. | The rate of formation of new organic matter by consumers. |
| 4. | The amount of energy released by the action of detritivores and decomposers in an ecosystem. |
| 1. | GPP is the total rate of photosynthesis, including both organic matter used in respiration and biomass accumulation; NPP is only the biomass accumulation. |
| 2. | GPP refers to the energy stored by consumers, while NPP refers to the energy stored by producers. |
| 3. | GPP is the total biomass accumulated, while NPP is the leftover energy after plants' metabolic needs are met. |
| 4. | NPP is always higher than GPP because it includes consumer productivity. |
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 |
| 1. | Decomposition is largely an anaerobic process. |
| 2. | In a particular climatic condition, decomposition rate is slower if detritus is rich in lignin and chitin, and quicker, if detritus is rich in nitrogen and water-soluble substances like sugars. |
| 3. | Warm and moist environment favour decomposition whereas low temperature and anaerobiosis inhibit decomposition. |
| 4. | Detritus is the raw material for decomposition |
Identify the incorrectly matched pair:
1. Carnivores -- secondary or tertiary consumer
2. Decomposers -- microbial heterotrophs
3. Herbivores -- primary consumer
4. Omnivores -- molds, yeasts and mushrooms
Consider the two statements:
| I: | Food chains rarely extend for more than 4 or 5 levels. |
| II: | Consumers at each level convert, on an average, only about 10% of the chemical energy in their food to their own organic tissue. |
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. Only I is correct.
4. Both I and II are incorrect.
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