The accompanying figure represents an ecological pyramid. It is
1. | Pyramid of numbers in a grassland |
2. | Pyramid of biomass in a fallow land |
3. | Pyramid of biomass in a lake |
4. | Energy pyramid in a spring |
A physical structure that is characteristic of each type of ecosystem is due to:
1. | Interaction between various biotic components of the ecosystem |
2. | Interaction between various abiotic components of the ecosystem |
3. | Interaction between various biotic and abiotic components of the ecosystem |
4. | Interaction of producers with abiotic components of the ecosystem |
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 |
In an ecosystem, the rate of production of organic matter during photosynthesis is called as its:
1. | Gross Primary productivity |
2. | Net Primary productivity |
3. | Secondary productivity |
4. | Non productivity |
The rate of formation of new organic matter by consumers in an ecosystem is known as:
1. | Gross Primary productivity |
2. | Net Primary productivity |
3. | Secondary productivity |
4. | Non-productivity |
The annual net primary productivity of whole biosphere is approximately:
1. | 25 billion tons | 2. | 55 billion tons |
3. | 70 billion tons | 4. | 170 billion tons |
By process of leaching during decomposition of detritus, water soluble :
1. | organic nutrients go down the soil horizon and get precipitated as available salts |
2. | inorganic nutrients go down the soil horizon and get precipitated as unavailable salts |
3. | organic nutrients go down the soil horizon and get precipitated as available salts |
4. | inorganic nutrients go down the soil horizon and get precipitated as available salts |
During decomposition of detritus, the step that is performed by bacteria and fungi includes:
1. Catabolism only
2. Catabolism and fragmentation
3. Leaching and catabolism
4. Fragmentation, Leaching and Catabolism
The three steps of decomposition occur:
1. sequentially, with catabolism being the last step.
2. sequentially, with leaching being the last step.
3. simultaneously.
4. sequentially, but not in a particular order.
Humus:
1. Is easily broken down by microbes
2. Undergoes decomposition rapidly
3. Serves as a reservoir of nutrients
4. Yields organic nutrients on mineralization