Energy Flow - Food Chain and Web - Unsolved Practice Paper
Chapter: Ecosystem | Topic: Energy Flow Food Chain and Web
ENERGY FLOW - FOOD CHAIN AND WEB - UNSOLVED PRACTICE PAPER
Topic: Energy Flow Food Chain and Web
Multiple Choice Questions
Q1. The flow of energy through an ecosystem, from producers to various levels of consumers, is generally described as:
- Cyclical, moving back and forth freely
- Unidirectional, flowing in one direction only
- Random, with no particular pattern
- Reversible, flowing equally in both directions
Q2. The grazing food chain begins with:
- Dead organic matter
- Producers, which are consumed by herbivores
- Decomposers
- Only carnivores
Q3. The detritus food chain begins with:
- Living green plants
- Dead organic matter, which is broken down by decomposers and detritivores
- Only top carnivores
- Sunlight directly
Q4. According to the general "10 percent law" of energy transfer between trophic levels, approximately what percentage of energy is transferred from one trophic level to the next?
- 100%
- 50%
- 10%
- 90%
Q5. A food web is best described as:
- A single, isolated food chain
- A network of interconnected food chains within an ecosystem
- A chart showing only producers
- A term with no ecological meaning
Short Answer Questions
Q6. Why is the flow of energy through an ecosystem described as unidirectional rather than cyclical?
Q7. Differentiate between a grazing food chain and a detritus food chain.
Q8. State the "10 percent law" of energy transfer, and explain its significance for the number of trophic levels typically seen in a food chain.
Q9. How does a food web differ from a single food chain?
Long Answer Questions
Q10. Explain the concept of energy flow through an ecosystem, describing how the laws of thermodynamics apply to the transfer of energy between trophic levels.
Q11. Discuss the "10 percent law" of energy transfer, explaining why this limited efficiency restricts the number of trophic levels typically found in most ecosystems.
APPLICATION / ANALYSIS
Q12. In a grassland ecosystem, producers capture 10,000 kcal of energy through photosynthesis. Using the 10 percent law of energy transfer, calculate the approximate amount of energy available to primary consumers (herbivores) and to secondary consumers (carnivores) at the next two trophic levels.
Q13. A student wonders why food chains rarely have more than four or five trophic levels, even though there is theoretically no upper limit to how many levels could exist. Explain, using your understanding of the 10 percent law, why energy loss at each trophic level limits the length of most food chains.