Assertion (A): | Decomposition process is slower if detritus is rich in lignin and cutin. |
Reason (R): | Decomposition is largely an oxygen requiring process. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true and (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | (A) is false but (R) is true. |
A: | Detrivores perform fragmentation. |
B: | The humus is further degraded by some microbes during mineralization. |
C: | Water soluble inorganic nutrients go down into the soil and get precipitated by a process called leaching. |
D: | The detritus food chain begins with living organisms. |
E: | Earthworms break down detritus into smaller particles by a process called catabolism. |
1. | D, E, A only | 2. | A, B, C only |
3. | B, C, D only | 4. | C, D, E only |
Match the following and select the correct option:
Column I | Column II | ||
(a) | Earthworm | (i) | Pioneer species |
(b) | Succession | (ii) | Detrivore |
(c) | Ecosystem service | (iii) | Natality |
(d) | Population growth | (iv) | Pollination |
1. A-(i), B-(ii), C-(iii), D-(iv)
2. A-(i), B-(ii), C-(iii), D-(iv)
3. A-(iii), B-(ii), C-(iv), D-(i)
4. A-(ii), B-(i), C-(iv), D-(iii)
Pheretima and its close relatives derive nourishment from:
1. Sugarcane roots
2. Decaying fallen leaves and soil organic matter
3. Soil insects
4. Small pieces of fresh fallen leaves of maize
Which of the following is not correct regarding the decomposition of wastes?
(a) | Low temperature inhibits decomposition |
(b) | Warm and moist environment favors the process |
(c) | The process is anaerobic |
(d) | It is slower if detritus is rich in proteins and carbohydrates |
(e) | Detritus is degraded into simpler inorganic substance by fungal and bacterial enzymes |
Choose the correct answer from the options given below:
1. | (b) and (c) only | 2. | (c), (a) and (d) only |
3. | (c) and (d) only | 4. | (c), (d) and (e) only |
The rate of decomposition is faster in the ecosystem due to the following factors, except:
1. | Detritus rich in sugars |
2. | Warm and moist environment |
3. | Presence of aerobic soil microbes |
4. | Detritus richer in lignin and chitin |
Statement I: | The rate of decomposition is not related to chemical composition of detritus and climatic factors. |
Statement II: | In a particular climatic condition, decomposition rate is faster if detritus is rich in lignin and chitin. |
Which one of the following processes during decomposition is correctly described?
1. | Humanification-Leads to the accumulation of a dark-coloured substance in humans which undergoes microbial action at a very fast rate |
2. | Catabolism-Last step decomposition under fully anaerobic condition |
3. | Leaching-Water soluble inorganic nutrients rise to the top layers of the soil |
4. | Fragmentation-Carried out by organisms such as earthworms |
1. Decomposition | 2. Catabolism |
3. Fragmentation | 4. Humification |
1. | is formed by humification of detritus as the first step of decomposition in an ecosystem. |
2. | is highly prone to rapid microbial action. |
3. | serves as a reservoir of nutrients. |
4. | is never degraded further in an ecosystem. |