Ecosystems & Energy Flow
Define “ecosystem.”
Ecosystem: A community of organisms interacting with each other and their physical environment.
What cycle involves evaporation?
Water cycle involves evaporation.
Define pollution:
Pollution = harmful substances in the environment.
What is conservation?
Conservation = protecting natural resources.
What is a trophic level?
Trophic level: A feeding level in an ecosystem.
Name one way carbon is released into the atmosphere.
Carbon released by combustion, respiration, decomposition.
What is habitat fragmentation?
Habitat fragmentation = splitting ecosystems into smaller pieces.
Define renewable resource.
Renewable = replenishes quickly (wind, solar).
Explain the 10% rule of energy transfer.
10% rule: Only ~10% of energy is passed to the next trophic level.
Explain nitrogen fixation.
Nitrogen fixation: bacteria convert N₂ into usable ammonia.
Describe biomagnification.
Biomagnification = toxins increase at higher trophic levels.
Describe one sustainable practice.
Sustainable practice = crop rotation, reduced water use, habitat restoration.
Difference: food chain vs food web.
Food chain = one path of energy; food web = many interconnected chains.
How does deforestation affect the carbon cycle?
Deforestation increases atmospheric CO₂ due to loss of carbon sinks.
Consequences of overfishing ?
Overfishing = population collapse, loss of biodiversity.
Difference: mitigation vs adaptation.
Mitigation = reduce causes; adaptation = adjust to effects.
Why are top predators rare in ecosystems?
Top predators require more energy and large territories; energy loss limits populations.
Describe eutrophication & its cause.
Eutrophication = nutrient runoff → algal blooms oxygen depletion.
Explain the greenhouse effect.
Greenhouse effect = gases trap heat in atmosphere.
Explain how policy can protect ecosystems.
Policy = laws protecting endangered species, regulating emissions, etc.