Ecosystems
What is the primary source of energy for most ecosystems on Earth?
the sun
Which relationship describes a lion eating a zebra?
Predation.
Which of these is a renewable resource: sunlight, natural gas, or petroleum?
sunlight
Which process returns water from the atmosphere to Earth's surface?
Precipitation.
Which role describes decomposers in an ecosystem?
Recycle nutrients from dead organisms (decomposers
What term describes the variety of species found in Earth's ecosystems?
biodiversity
Name one major effect of using fossil fuels on Earth’s atmosphere.
Increases atmospheric carbon dioxide / greenhouse gases -> climate change.
Which process in the nitrogen cycle converts atmospheric nitrogen into a form plants can use?
Nitrogen fixation.
In a food web, energy flows from which groups of organisms to which other groups?
From producers to consumers to decomposers (energy decreases at each trophic level).
Give one real-world example of mutualism and briefly explain how both species benefit.
bee and flower (bee gets nectar/pollen; flower gets pollinated).
Which process helps transform remains of organisms into fossil fuels: pressure, sunlight, or wind?
Pressure (and heat over long time).
If all decomposers were removed from an ecosystem, what would likely happen?
Dead organisms and waste would accumulate; nutrient recycling would stop.
Give one example of a biotic factor and one example of an abiotic factor in an ecosystem.
Example biotic = bacteria or trees; abiotic = sunlight or water.
Describe what happens to energy as it moves through trophic levels in a food chain.
Energy decreases at each trophic level (lost as heat/metabolic processes).
Complete the sentence: "Fossil fuels are ______ resources that are ______ distributed on Earth."
Nonrenewable; unevenly (or unevenly) distributed.
Explain briefly how geothermal energy works (one sentence).
Uses Earth's internal heat to make steam to drive turbines.
Explain how biodiversity can make an ecosystem more stable. Include one specific example.
More species provide redundancy and varied responses to change (e.g., diverse pollinators help crop production after a disturbance).
Define resilience in an ecosystem and describe one action people could take to improve ecosystem resilience.
Resilience = ability to recover after disturbance; action: protect habitat corridors, reduce pollution, restore native species.
Explain why wood is considered a renewable resource and give one condition that must be met for it to remain renewable.
Wood regrows through tree growth and sustainable harvesting; condition: managed harvesting/replanting.
A friend says finding petroleum in an area means marine organisms once lived there. Is this correct?
Yes — often petroleum forms from ancient marine organisms buried and transformed under pressure and heat; presence of petroleum can indicate past marine environments, but geological processes and time are required.