Practice Questions
List two examples of human-made ecosystems mentioned in the text.
Define what a trophic level is.
Create a food web for a grassland ecosystem that includes grass, a grasshopper, a frog, a snake, and a hawk. Justify the position of each organism and identify the different trophic levels present.
Define the term 'ecosystem'.
Apply the concept of trophic levels to classify a human whose diet consists exclusively of fruits, vegetables, and grains.
Formulate a hypothesis regarding the long-term impact on soil fertility in a forest ecosystem if all decomposers were suddenly eliminated.
Recall the chemical formula for an ozone molecule.
Name the three main functional groups of organisms in an ecosystem based on how they obtain sustenance.
In a food chain consisting of grass, a deer, and a tiger, demonstrate which organism occupies the third trophic level.
Analyze the consequences for an ecosystem, such as a forest, if all decomposer organisms like bacteria and fungi were suddenly eliminated.
Critique the practice of using disposable paper cups as a completely 'environment-friendly' alternative to plastic cups by evaluating their entire life cycle.
Identify the trophic levels for each organism in the following food chain: Grass → Deer → Lion.
Explain the difference between biodegradable and non-biodegradable substances, providing one example for each.
Describe the primary role of decomposers in an ecosystem and explain why they are essential.
Name the organization that succeeded in forging an international agreement in 1987 to freeze the production of CFCs.
Explain the difference between biotic and abiotic components of an ecosystem, providing two examples for each.
Define a food web.
In a terrestrial food chain, if the energy available at the producer level (grass) is , calculate the amount of energy that would be available to the secondary consumer (fox) that feeds on the primary consumer (rabbit).
Examine the statement: 'A food web provides more stability to an ecosystem than a simple food chain.' Analyze this statement with an appropriate example.
Justify why food chains in most ecosystems are limited to three or four trophic levels. Use the 10% law of energy transfer in your justification.
In a pond ecosystem, algae receive J of sunlight. Calculate the amount of energy that would be available to the large fish in the food chain: Algae → Zooplankton → Small Fish → Large Fish. Justify your calculations.
Summarize the main reason why food chains generally consist of only three or four steps.
Analyze why most food chains are limited to only three or four trophic levels.
If the producers in an ecosystem capture of solar energy, calculate the amount of energy that would be available to the organisms at the fourth trophic level (tertiary consumers).
A farmer sprays a non-biodegradable pesticide on his crops near a river. Demonstrate the pathway through which this pesticide could accumulate in the body of a person who consumes fish from that river.
Examine why an aquarium requires periodic cleaning to sustain its fish, whereas a natural pond ecosystem is largely self-cleaning.
Critique the argument that the use of non-biodegradable pesticides is a necessary evil for maximizing agricultural output, from an ecological standpoint.
Evaluate the ecological significance of an omnivore in maintaining the stability of a food web.
Evaluate the global response to ozone depletion, focusing on the role of chlorofluorocarbons (). Was the international agreement mentioned in the text a success? Justify your answer.
A food chain has phytoplankton that capture kJ of energy. Justify, with calculations, why it is ecologically unfeasible for this food chain to sustain a fifth trophic level.
Justify the statement: 'The flow of energy in an ecosystem is unidirectional, while the flow of matter is cyclic.'
Compare the role and formation of ozone () in the stratosphere versus its presence at ground level.
Contrast the long-term environmental impact of disposing of vegetable peels with that of disposing of plastic bags.
Examine the phenomenon of biological magnification using the following aquatic food chain: Algae → Zooplankton → Small Fish → Large Fish → Fish-eating Bird. Explain why the bird would have the highest concentration of a non-biodegradable pesticide like DDT.
Propose a comprehensive waste management strategy for a school campus to minimize its environmental footprint. Your proposal should address biodegradable waste, non-biodegradable waste, and awareness.
Compare and contrast a natural ecosystem like a forest with an artificial ecosystem like an aquarium, focusing on nutrient cycling, energy flow, and stability.
Explain the phenomenon of biological magnification.
Evaluate the claim that replacing all non-biodegradable waste with biodegradable waste would completely solve our waste management problems and have no negative impact on the environment.
Analyze the chemical process by which chlorofluorocarbons (CFCs) lead to the depletion of the ozone () layer in the stratosphere.
Design an experiment to investigate the phenomenon of biological magnification using a simple aquatic food chain model in a laboratory setting.
Explain the flow of energy in an ecosystem. Why is this flow considered unidirectional? Also, summarize the ten percent law of energy transfer.
Describe how the ozone layer is formed in the upper atmosphere and explain its importance. Also, name the category of synthetic chemicals responsible for its depletion.
Propose a set of three key regulations a government could implement to control the environmental damage caused by single-use, non-biodegradable plastics. Justify each regulation.
Design a closed, self-sustaining aquatic ecosystem in a large sealed glass jar. Justify the inclusion of each biotic and abiotic component you choose.
Compare the ideal methods for managing household kitchen waste (like vegetable peels) and plastic waste. Analyze the long-term environmental consequences of improperly disposing of each.