Q. No.
Consider the given two statements:
I:
Humus has the ability to store nutrients.
II:
Humus is a colloidal substance and increases the cation-exchange capacity of the soil.
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.
Consider the given two statements:
| I: | Humus has the ability to store nutrients. |
| II: | Humus is a colloidal substance and increases the cation-exchange capacity of the soil. |
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.
Which of the following representations shows the pyramid of numbers in a forest ecosystem?
| 1. | A | 2. | B |
| 3. | C | 4. | D |
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 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 |
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
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 |
The most relevant abiotic ecological factor for organisms is:
| 1. | Temperature | 2. | Water |
| 3. | Light | 4. | Soil |
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 |
Identify the likely organisms (a), (b), (c) and (d) in the food web shown below :
|
(a) |
(b) |
(c) |
(d) |
|
|
1 |
Dog |
Squirrel |
Bat |
Deer |
|
2 |
Rat |
Dog |
Tortoise |
Crow |
|
3 |
Squirrel |
Cat |
Rat |
Pigeon |
|
4 |
Deer |
Rabbit |
Frog |
Rat |
Given below is a simplified model of phosphorus cycling in a terrestrial ecosystem with four blanks (A-D). Identify the blanks.
| A | B | C | D | |
| 1. | Rock minerals | Detritus | Litter fall | Producers |
| 2. | Litter | Producers | Rock minerals | Detritus |
| 3. | Detritus | Rock minerals | Producers | Litter fall |
| 4 | Producers | Litter fall | Rock minerals | Detritus |
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