Q. No.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
The most relevant abiotic ecological factor for organisms is:
| 1. | Temperature | 2. | Water |
| 3. | Light | 4. | Soil |
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 |
During the decomposition of complex organic matter:
| I: | Fragmentation of detritus creates smaller particles. |
| II: | Due to leaching water-soluble inorganic nutrients get precipitated. |
| III: | Catabolism by fungal and bacterial enzymes degrades detritus to simple organic monomers. |
| IV: | Humus is highly resistant to microbial action |
| V: | Mineralization is a rapid process of release of inorganic nutrients from the humus |
1. All except III are correct
2. All except III and IV are correct
3. All except III and V are correct
4. Only III is correct
Which of the following is not a correct difference between a grazing food chain [GFC] and a detritus food chain [DFC]?
|
|
GFC |
DFC |
|
1. |
Major conduit of energy flow in aquatic ecosystem |
Major conduit of energy flow in terrestrial ecosystem |
|
2. |
Much larger energy flows through it |
Much smaller energy flows through it |
|
3. |
Begins with producers |
Begins with dead organic matter |
|
4. |
Energy for this food chain comes from the sun |
Energy for this food chain comes from the remains of detritus |
Consider the two statements:
| I: | Phosphorus is much more important as a limiting nutrient in aquatic systems. |
| II: | Phosphorus is generally much less soluble than nitrogen, it is leached from the soil at a much slower rate than nitrogen. |
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 and II is incorrect.
4. Both I and II are correct.
Which of the following ecosystem characteristics that changes during succession is not correctly matched?
|
|
Characteristics |
Seral stages |
Climax |
|
1. |
Size of individuals |
Small |
Large |
|
2. |
Ecological niches |
Few, generalized |
Many, specialized |
|
3. |
Food chains and webs |
Simple |
Complex |
|
4. |
Efficiency of energy use |
High |
Low |
The correct sequence in primary hydrarch succession in early seral stages would be:
| 1. | Submerged plant – Submerged free-floating plant – Reed swamp – Marsh meadow |
| 2. | Submerged free-floating plant – Submerged plant – Reed swamp – Marsh meadow |
| 3. | Submerged plant – Submerged free-floating plant – Marsh meadow – Reed swamp |
| 4. | Submerged free-floating plant – Reed swamp – Submerged plant – Marsh meadow |
| Assertion (A): | We generally undervalue the magnitude of ecosystem services that benefits us. |
| Reason (R): | We do not attach a monetary value to the services of natural ecosystems. |
| 1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
| 3. | (A) is true but (R) is false. |
| 4. | Both (A) and (R) are false. |
- If both the assertion and the reason are true and the reason is a correct explanation of the assertion
- If both the assertion and reason are true but the reason is not a correct explanation of the assertion
- If the assertion is true but the reason is false
- If both the assertion and reason are false
Nitrogen is often a limiting nutrient in terrestrial ecosystems because:
| 1. | the percentage of nitrogen in the atmosphere is low |
| 2. | atmospheric nitrogen is primarily in the stratosphere |
| 3. | dinitrogen cannot be used directly by the organisms |
| 4. | there are regional fluctuations in nitrogen levels in the atmosphere |
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