The minimum requirement for an ecosystem to recycle nutrients present in it would be:
1. | producers |
2. | producers and decomposers |
3. | producers, primary consumers, and decomposers |
4. | producers, primary consumers, secondary consumers, and decomposers |
Consider the following statements:
The rate of decomposition is high if:
I: | The detritus is rich in lignin and chitin. |
II: | The detritus is rich in nitrogen and sugars. |
III: | The environmental conditions are warm and moist. |
Which of the above statements are true?
1. | I and II only | 2. | I and III only |
3. | II and III only | 4. | I, II, and III |
Assertion (A): | Low temperature and anaerobiosis inhibit decomposition resulting in build-up of organic chemicals. |
Reason (R): | Most decomposers are anaerobic psychrophiles. |
In the light of the above statements, choose the most appropriate answer from the options given below:
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. |
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
Decomposers like fungi and bacteria are :
i. | Autotrophs |
ii. | Heterotrophs |
iii. | Saptrotrophs |
iv. | Chemo-autotrophs |
Choose the correct answer :
1. | i and ii | 2. | i and iv |
3. | ii and iii | 4. | i and iii |
If decomposers go extinct on Earth:
1. | Detritivores will replace them |
2. | Primary production will increase |
3. | Nutrients will accumulate in dead plants and animals |
4. | There will be no effect on carnivores |
Sometimes the term "detritivore" is used interchangeably with:
1. | decomposers | 2. | primary consumers |
3. | secondary consumers | 4. | autotrophs |
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.