The study of how living things interact with each other and with their surroundings.
What is Ecology?
An organism that makes its own food, like a plant.
What is a primary producer? (Autotrophs also acceptable)
A diagram that shows who eats whom in one single line.
What is a food chain?
The cycle in which water rises into the air, forms clouds, and falls back to Earth as rain or snow.
What is the water cycle?
A nonliving part of an ecosystem, like sunlight, water, or soil.
What is an abiotic factor?
All the members of one species living together in one area.
What is a population?
A consumer that eats only plants.
What is an herbivore?
Many food chains linked together, showing all the feeding relationships in an ecosystem.
What is a food web?
The process in which bacteria change nitrogen gas from the air into a form plants can use.
What is nitrogen fixation?
A consumer that eats both plants and animals.
What is an omnivore?
A community plus all of its nonliving surroundings.
What is an ecosystem?
The process that uses sunlight to turn water and carbon dioxide into sugar.
What is photosynthesis?
One step in the flow of energy through an ecosystem, such as producers or meat eaters.
What is a trophic level?
The one nutrient that runs out first and stops the growth of plants or algae in an ecosystem.
What is a limiting nutrient?
The total mass of living things at one trophic level; it shrinks at each level up the pyramid.
What is biomass?
Ecologists use three main research methods: observation, experimentation, and this computer-based method for studying systems too big or too slow to study directly.
What is modeling?
Fungi and bacteria that break down dead things completely and return nutrients to the soil.
What are decomposers?
Only about this percentage of the energy at one trophic level moves up to the next level.
What is 10 percent?
In this cycle, a nutrient moves from rock into soil and water but does not usually enter the atmosphere at all.
What is the phosphorus cycle?
A diagram shaped like a pyramid, with a wide base of producers and a narrow top, that shows how energy or biomass drops at each level.
What is an ecological pyramid?
Name the levels of ecological organization in order, from smallest to largest.
What are species, population, community, ecosystem, biome, and biosphere?
Deep-sea vent bacteria make food without sunlight using this process, which runs on chemicals instead of light.
What is chemosynthesis?
Explain why food chains are usually short, with only three or four links.
Most energy is used by organisms or lost as heat at each level, so little remains to support more levels.
Explain why the phosphorus cycle never includes an atmospheric stage the way the carbon and nitrogen cycles do.
Phosphorus is not found as a gas; it stays in rocks, soil, water, and living things.
Explain how fertilizer washing off farm fields can cause an algal bloom in a pond.
The fertilizer adds extra limiting nutrients, so algae grow suddenly and hugely, hurting the ecosystem.