Energy flow and nutrient cycling are two important components of an ecosystem. What will be true comparison of the two?
1. | The amount of energy is much greater than the amount of nutrients |
2. | Organisms always need nutrients, but they don't always need energy |
3. | Nutrients are recycled, but energy is not |
4. | Organisms always need energy, but they don't always need nutrients |
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
Primary succession takes a very long time when compared to secondary succession, primarily, because:
1. immigration of pioneer species takes time
2. soil formation is a very slow process
3. there is a low availability of ecological niches
4. environmental conditions are highly variable
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.
Of the total solar radiation that falls on the leaves of the plants, about what percent is captured by them?
1. | 1 – 5 % | 2. | 2 – 10 % |
3. | 40 – 50 % | 4. | 90 – 100 % |
Identify the incorrect statement regarding phosphorus cycle in an ecosystem:
1. | Phosphorus frequently limits the primary productivity of an ecosystem |
2. | Phosphorus is a nutrient that typically cycles within most localized area |
3. | Gaseous exchange of phosphorus between organisms and environment is negligible |
4. | The largest reservoir of phosphorus in the biosphere is the ocean |
Consider the given two statements:
I: | In most ecosystems, all the ecological pyramids are largely upright. |
II: | Pyramid of energy can be a notable exception to the above rule. |
1. Both I and II are correct.
2. Both I and II are incorrect.
3. Only II is correct.
4. Only I is correct.
On the land, almost all primary production is performed by:
1. | Phytoplanktons | 2. | Algae |
3. | Mosses and Liverworts | 4. | Vascular plants |
Consider the given two statements:
I: | Human burning of fossil fuels today is creating large contemporary imbalances in the carbon cycle. |
II: | It has significantly increased the rate of release of carbon dioxide into the atmosphere. |
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. |
If we put a price tag on nature’s life-support services, about 50 % of the total cost will be accounted for by:
1. Recreation and nutrient cycling
2. Soil formation
3. Climate regulation
4. Habitat for wildlife