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
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 % |
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 |
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. |
Suppose in an area, the energy present in total incident sunlight falling on primary producers is 10,00,000 J and about 10,000 J is converted by them into biomass. What percent of PAR have the primary producers been able to convert?
1. | 1 % | 2. | 2 % |
3. | 10 % | 4. | 20 % |
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 |
Net primary productivity is the gross primary productivity minus:
1. | that which is consumed by herbivores |
2. | that which is consumed by the producer in metabolism |
3. | secondary productivity |
4. | loss due to mortality |