ECOLOGY BASICS
What is the difference between abiotic and biotic factors?
Abiotic = non-living; Biotic = living components of an ecosystem.
What do autotrophs do that heterotrophs cannot?
Autotrophs make their own food (like plants via photosynthesis).
Define population density.
The number of individuals of a species in a given area.
What is mutualism?
A relationship where both species benefit.
What is biodiversity?
The variety of living species in an ecosystem or on Earth.
What is the term for all the populations in an area?
A Community
What’s the main source of energy for almost all ecosystems?
Sunlight.
What are the three types of population distribution?
Random, Uniform, and Clumped.
Give an example of commensalism.
Barnacles on whales – barnacle benefits, whale is unaffected.
What’s the difference between primary and secondary succession?
Primary: no soil, starts from bare rock; Secondary: soil already present.
Put these in order from smallest to largest: population, organism, biome, ecosystem, biosphere, community.
Organism → Population → Community → Ecosystem → Biome → Biosphere
What’s the name of the “edible” molecule plants make from sunlight?
Glucose
What is carrying capacity?
The maximum population size an environment can sustain.
What makes a non-native species “invasive”?
It causes harm to the ecosystem by outcompeting or harming native species.
What organism often begins primary succession?
Pioneer species like lichen or moss.
What does an ecologist study? Give two examples.
Interactions in environments; e.g., forest fires' effects or pesticide effects on bees.
In a food chain, what does each arrow represent?
The flow of energy from one organism to the next.
Differentiate between exponential and logistic growth.
Exponential: rapid, unlimited growth; Logistic: slows as carrying capacity is reached.
What damage did lake trout cause in Yellowstone Lake?
They preyed on native cutthroat trout, altering the ecosystem.
What is a climax community?
A stable, mature ecosystem that has reached equilibrium.
What’s a keystone species and why is it important?
A species that many others depend on; its removal drastically alters the ecosystem.
Why does only 10% of energy move up each level in an ecological pyramid?
Energy is used for life processes like respiration, and lost as heat or waste.
List 3 limiting factors that affect population growth.
Food, water, space, disease, predation, etc.
How can invasive species be controlled or prevented?
Education, eradication programs, laws, and preventing their spread.
How do humans disrupt natural ecological succession?
Through deforestation, pollution, agriculture, and urbanization.