Ecosystem Basics
What is an ecosystem?
A system of living and non-living things interacting in a specific area.
What is a desert?
A dry biome with low rainfall, often hot, with sparse vegetation.
What is the main source of energy in most ecosystems?
The Sun.
Name the steps in the water cycle.
Evaporation, condensation, precipitation, infiltration, runoff.
What is the difference between predator and prey?
Predator hunts/eats; prey is the organism that gets eaten.
Define abiotic factor.
A non-living part of an ecosystem, like sunlight, water, or temperature.
What are the temperature and rainfall patterns of rainforests?
Warm year-round with high rainfall (over 200 cm per year).
What is a food web?
A diagram showing many interconnected food chains in an ecosystem.
What’s the carbon cycle?
Movement of carbon through atmosphere, plants, animals, and soil via photosynthesis and respiration.
Give an example of mutualism.
Bees pollinating flowers (both benefit).
What’s a niche?
The role a species plays in its environment.
What are the characteristics of a tundra?
Cold, dry, permafrost layer, short growing seasons, few trees.
Explain the 10% rule.
Only 10% of energy is passed to the next trophic level; the rest is lost as heat.
What is nitrogen fixation?
When bacteria convert nitrogen gas (N₂) into ammonia or nitrates plants can use.
What is parasitism?
One organism benefits , the other is harmed, like a tick on a deer.
What is an example of a biome.
A desert, rainforest, tundra, or grassland.
How are marine and freshwater biomes different?
Marine = saltwater (oceans, coral reefs);
Freshwater = lakes, rivers, ponds with low salt.
What are trophic levels?
Levels in a food chain: producers, primary consumers, secondary consumers, etc.
Why is phosphorus important?
It helps form DNA, RNA, and ATP — critical for living organisms
What is an invasive species?
A non-native species that spreads quickly and harms native species and ecosystems.
What are ecosystem services?
Benefits humans get from ecosystems like clean air, pollination, and water filtration.
How do humans impact biomes?
Through deforestation, pollution, climate change, and habitat destruction.
What is primary productivity?
The rate at which producers make energy through photosynthesis.
How do humans affect biogeochemical cycles?
Burning fossil fuels, fertilizer use, deforestation.
What is a keystone species?
A species that has a large impact on its ecosystem; if removed, the whole system changes