UPSC Mains 2022 GS3 Q6 — Environmental Science
Each year a large amount of plant material, cellulose, is deposited on the surface of Planet Earth. What are the natural processes this cellulose undergoes before yielding carbon dioxide, water and other end products? (Answer in 150 words)
Question Decoded — examiner's intent
- Directive verbs
- What are
- Scope keywords
- plant materialcellulosenatural processescarbon dioxide, water and other end products
- Implicit sub-parts
- Mechanisms of physical and chemical breakdown of cellulose in different environments.
- Role of decomposers like fungi, bacteria, and detritivores in the enzymatic degradation process.
- Differentiation between aerobic and anaerobic decomposition pathways and their respective end products.
- Mention of the carbon cycle link to justify the transition from biomass to inorganic compounds.
- Common pitfalls
- Writing a generic essay on the importance of forests or biodiversity instead of the biochemistry of decomposition.
- Failing to mention specific enzymes like cellulase or specific organisms like ruminants and termites.
- Ignoring anaerobic processes (methanogenesis) which occur in wetlands or peatlands.
- Focusing too much on the industrial uses of cellulose rather than the 'natural processes' specified.
- Dimensions required
- Biological/EnzymaticChemical (Oxidation/Hydrolysis)Ecological (Nutrient Cycling)Environmental (Climatic factors affecting rate)
- Marks allocation hint
Allocate 30 words to define cellulose and its abundance. Devote 90 words to the core technical processes: fragmentation, leaching, catabolism, and humification, including the role of cellulase. Use the final 30 words to distinguish between aerobic (CO2) and anaerobic (CH4) outputs and the completion of the nutrient cycle.
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