HB Chapter 3 Review

All life on Earth exists in a region known as
The biosphere

Groups of different species that live together make up a

Autotrophs are organisms that
Use the energy they take in from the environment to convert inorganic molecules into complex organic molecules

The series of steps in which a large fish eats a small fish that has eaten algae is a
Food chain

What is an example of a decomposer?

The total mass of living tissue at each trophic level can be shown in a
Biomass pyramid

Nutrients move through a system in
Biogeochemical cycles

In the nitrogen cycle, bacteria that live on the roots of plants
Change nitrogen gas into ammonia in process called nitrogen fixation

What biogeochemical cycle does not involve a stage where the chemical enters the atmosphere?
Phosphorus cycle

When an ecosystem is limited by a single nutrient that is either scarce or cycles slowly, this substance is called a
Limiting nutrient

What are the levels of organization within the biosphere, from smallest to largest?
Individual, population, community, ecosystem, biome, biosphere

How do scientists use modeling to study ecological changes?
Could make charts to simplify large scale changes

How is sunlight important to most ecosystems?
Main power source

Differences between autotroph and heterotroph?
Autotroph makes its own food and heterotroph consumes autotrophs or other heterotrophs for energy

Which group of organisms is always found at the base of the food chain or food web

What are three types of ecological pyramids?
Energy pyramids, biomass pyramids, and pyramid of numbers

Why is the transfer of energy and matter in a food chain only about 10 percent efficient?
Organisms use 10 percent of their energy for life processes and the rest is lost as heat

What is A biogeochemical cycle?
Cycles which show how energy and matter move through the ecosystem

Explain the process of nitrogen fixation
Bacteria which live on roots of plants called legumes convert nitrogen gas into ammonia