1. Unit: Ecology Chapter 11: Ecosystems and Biomes
Chapter 12: Interactions Within Ecosystems
11.1:Ecosystems support life
11.2: Matter cycles through ecosystems
11.3: Energy flows through ecosystems
11.4: Biomes contain many ecosystems

2. Review True or False? If false, correct them:
Organisms in soil are an example of abiotic factors
Organisms in soil are an example of biotic factors
The amount of light available in an ecosystem affects the types and amount of plant life that will grow there
True
Plants use energy to make sugars through photosynthesis

3. All ecosystems need certain materials
An organism’s needs are met by: materials, or matter, required by all living things
Ex: food and water
All materials an organism takes in are returned to the ecosystem – during or after its life
This continuous movement of matter through living and nonliving parts = cycle (a series of events that happens over and over again)
Matter in an ecosystem may change form, but never leaves
It is cycled through the ecosystem
Three of the most important cycles in ecosystems involve:
Water, carbon, and nitrogen

4. Water cycles through ecosystems
condensation
precipitation
evaporation
groundwater
runoff
Surface: lakes, rivers, oceans
Underground: between soil particles and cracks in rocks
Glaciers and ice sheets
Bodies
Water: Hydrogen and Oxygen (H2O)
Changes state as it cycles through the ecosystem: solid (ice/snow), liquid, gas (water vapor)
Precipitation: rain, snow, sleet, mist, hail
Evaporation: liquid  gas
Condensation: gas  liquid
Respiration: animals release water vapor when they breathe
Transpiration: plants release water vapor, usually through their leaves

6. Carbon cycles through ecosystems
Carbon is found in all living things
Carbon enters living parts of an ecosystem through carbon dioxide gas
Plants: photosynthesis
Carbon dioxide is used to produce sugars (carbon compounds found in food and all living matter)
Organisms break down the carbon compound to release sugars in food: called respiration
Carbon is released and cycled back into the atmosphere as carbon dioxide
When living things die and decay, the rest of the carbon making up that organism is released
Carbon is stored underground as the remains of plants and animals that have been buried for millions of years decay slowly
This decay changes the dead organisms into fossil fuels (ie coal and oil)
When humans burn these fossil fuels (combustion), dust particles and gases containing carbon are released to the environment

7. photosynthesis
respiration
fossil fuels

8. Nitrogen cycles through ecosystem
4/5 of the air we breathe is nitrogen – a clear, colorless gas
We also need nitrogen to live, and we must get it from plants
Plants cannot use pure nitrogen gas either
Plants absorb certain compounds of nitrogen (“fixed” nitrogen) and can absorb it through their roots
Nitrogen can get into soils
via lightning (the strike breaks apart pure nitrogen)
Rain
Bacteria that fix nitrogen (also found in the oceans)
When organisms die, decomposers in the ocean or soil break them down:
nitrogen is then returned to the atmosphere by bacteria that can break down nitrogen compounds into nitrogen gas

9. http://www. classzone. com/books/ml_sci_ca6/page_build. cfm

11. Links Chapter 16: http://www.uiweb.uidaho.edu/hesg/model.html Biomes
Ecosystems: