Define : (i) Biomass (ii) Anaerobic degradation
Define : (i) Biomass (ii) Anaerobic degradation
Official answer
(i) Biomass: It refers to the total amount of organic matter present in the bodies of living organisms at a particular trophic level in an ecosystem. In the context of energy flow, it represents the chemical energy stored that is available for the next trophic level.
(ii) Anaerobic degradation: It is the process by which microorganisms (decomposers) break down complex organic substances into simpler substances in the absence of free molecular oxygen ().
Marking scheme
- 1.Correct definition of Biomass as organic matter at a trophic level. (1 mark)
- 2.Correct definition of Anaerobic degradation as breakdown in the absence of oxygen. (1 mark)
Hint
Relate biomass to the 'organic matter' mentioned in the 10% law, and anaerobic to the absence of the oxygen mentioned as essential for aerobic life.
Quick oral answer
Biomass is the organic material of living things. Anaerobic degradation is the breakdown of waste by microbes without using oxygen.
Common mistakes
- 1.Confusing biomass with total weight (it specifically refers to organic matter).
- 2.Thinking degradation only happens with oxygen; many waste processes are anaerobic.
Analysis and explanation
The text mentions that only 10% of food eaten is turned into an organism's 'own body' and made available for the next level; this 'body' mass is the biomass. Regarding degradation, the text discusses how enzymes and bacteria break down substances. While the text focuses on aerobic life, degradation in the absence of oxygen is termed anaerobic, often occurring in deep soil or waste pits where oxygen is limited.
Interesting facts
The 10% law explains why biomass decreases significantly as we move up the trophic levels in a food chain.
Question details
Q12 of 41 questions
- Board
- CBSE
- Class
- Class 10
- Subject
- Science
- Year
- 2011
- Section
- Section A
- Marks
- 2
- Type
- Short Answer
- Chapter
- Our Environment
- Topic
- Energy Flow and Waste Management
- Bloom's level
- Understanding
- Syllabus topic
- Ecosystem, Environmental problems, Waste production and their solutions.
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Frequently asked questions
How many marks does this question carry in CBSE Class 10 Science 2011?
This question carries 2 marks in the CBSE Class 10 Science 2011 examination.
Which chapter does this question come from in Science?
This question is from the chapter "Our Environment" in the CBSE Class 10 Science syllabus.
What topic does this question cover in Science?
This question covers the topic "Energy Flow and Waste Management" from CBSE Class 10 Science.
What type of question is this in the CBSE Class 10 Science 2011 paper?
This is a Short Answer question from Section A in the CBSE Class 10 Science 2011 paper.