Statement I: | There is unidirectional movement of energy towards the higher trophic levels and its dissipation and loss as heat to the environment. |
Statement II: | Nutrients are never lost from the ecosystems, rather they are recycled time and again indefinitely. |
Statement I: | Tropical land areas have the highest rates of production. |
Statement II: | Oceans have low productivity. |
Statement I: | The terms detritivore and decomposer describe same organisms. |
Statement II: | Both are unable to ingest discrete lumps of matter, but instead live by absorbing and metabolizing on a molecular scale. |
Assertion (A): | Most ecosystems would vanish if the sun were not, continuously, providing energy to the Earth. |
Reason (R): | Ecosystems and living organisms defy second law of thermodynamics. |
1. | Both (A) and (R) are True but (R) does not explain (A). |
2. | (A) is True but (R) is False. |
3. | (A) is False but (R) is True. |
4. | Both (A) and (R) are True and (R) explains (A). |
Statement I: | No energy that is trapped into an organism remains in it forever. |
Statement II: | All animals depend on plants [directly or indirectly] for their food requirements. |
Statement I: | A is primary succession and B is secondary succession. |
Statement II: | A will be much faster in pace than B. |
1 | 2 | 3 | 4 | |
A. | Phyto- plankton |
Zoo- plankton |
Phyto- plankton |
Phyto- plankton |
B. | Submerged plant | Submerged free floating plant |
Submerged plant | Reed swamp |
C. | Submerged free floating plant | Reed swamp | Scrub | Submerged plant |
D. | Reed swamp | Marsh meadow | Submerged free floating plant |
Marsh meadow |
E. | Marsh meadow | Scrub | Reed swamp | Submerged free floating plant |
F. | Scrub | Submerged plant |
Marsh meadow | Scrub |
Statement I: | Rocks are the natural reservoirs where phosphorus is present in the form of phosphates. |
Statement II: | Minute amounts of phosphates dissolve in soil solution when rocks are weathered and are absorbed by the roots of the plants. |
Statement III: | Herbivores and other animals obtain phosphorus from plants. |
Statement IV: | Phosphate solubilising bacteria decompose waste products and dead organisms releasing phosphorus. |
Statement V: | Gaseous exchange of phosphorus between organisms and environment is significant. |
1. | All except Statement V are correct. |
2. | All except Statement I and Statement V are correct. |
3. | Only Statement I, Statement II and Statement III are correct. |
4. | All Statements are correct. |
I: | A pyramid of numbers shows graphically the population, or abundance, in terms of the number of individual organisms involved at each level in a food chain. |
II: | The pyramid shows the number of organisms in each trophic level and it does not consider individual sizes or biomass. |
III: | It is not necessary that the pyramid is always upright. For example, it will be inverted if beetles are feeding from the output of forest trees, or parasites are feeding on large host animals. |
1. | Only I and II |
2. | Only I and III |
3. | Only II and III |
4. | I, II and III |
I: | The respiration cost increases sharply along successive higher trophic levels. |
II: | There can be lower amounts of biomass at the bottom of the pyramid if the rate of primary production per unit biomass is high. |
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. |