1. Write everything that is underlined
Section 22“Cycles”
Write everything that is underlined

2. KEY CONCEPT: Matter cycles in and out of an ecosystem.

3. I. The Water Cycle 1. The hydrologic, or water cycle is the circular pathway of water on Earth.
precipitation
condensation
transpiration
evaporation
water storage
in ocean
surface
runoff
lake
groundwater
seepage

4. 2. Key terms for the water cycle:
Precipitation: moisture that falls to the ground (rain, snow, sleet, hail)
Evaporation: changing from liquid to gas (water to water vapor)
Transpiration: plants give off water vapor from their leaves to the air
Condensation: changing from gas to a liquid (little water droplets form on the outside of a cold glass of lemonade - that’s condensation)

5. II. Oxygen Cycle:
1. Plants make food by photosynthesis
They use carbon dioxide (CO2) to make oxygen (O2)
2. Animals breathe out carbon by respiration
They use oxygen (O2) and breathe out carbon dioxide (CO2)
By the way … humans are animals too

6. Example: Oxygen Cycle:
respiration
carbon
dioxide
photosynthesis

7. Activity
Draw, label, color, and explain the water cycle and oxygen cycles on a sheet of paper.
Page 413 figure & 13.13
Due tomorrow

8. 1. Carbon is the building block of life.
III. Carbon Cycle
1. Carbon is the building block of life.
The carbon cycle moves carbon from the atmosphere, through the food web, and returns to the atmosphere.
Carbon is emitted by the burning of fossil fuels (like oil, gasoline, and coal)

9. Carbon Cycle: notice photosynthesis and respiration are back … they both involve CO2 (now we’re looking at the C for carbon)
fossil fuels
photosynthesis
carbon dioxide
dissolved in water
decomposition
of organisms
respiration
carbon
dioxide
in air
combustion

10. IV. The Nitrogen Cycle
The nitrogen cycle mostly takes place underground.
Some bacteria convert gaseous nitrogen into ammonia through a process called nitrogen fixation.
Some nitrogen-fixing bacteria live in nodules on the roots of plants; others live freely in the soil.
nitrogen in
atmosphere
animals
denitrifying
bacteria
nitrifying
ammonium
ammonification
decomposers
plant
nitrogen-fixing
bacteria in soil
bacteria in roots
nitrates
nitrites

11. Nitrifying bacteria change the ammonium into nitrate.
Ammonia released into the soil is transformed into ammonium.
Nitrifying bacteria change the ammonium into nitrate.
nitrogen in
atmosphere
animals
denitrifying
bacteria
nitrifying
ammonium
ammonification
decomposers
plant
nitrogen-fixing
bacteria in soil
bacteria in roots
nitrates
nitrites
Nitrogen moves through the food web and returns to the soil during decomposition.

12. Phosphate is released by the weathering of rocks.
V. Phosphate Cycle
Phosphate is released by the weathering of rocks.
Phosphorus leaches into groundwater from the soil and is locked in sediments.
Both mining and agriculture add phosphorus into the environment.
geologic uplifting
rain
weathering of
phosphate from rocks
runoff
sedimentation
forms new rocks
leaching
phosphate in solution
animals
plants
decomposers
phosphate
in soil

13. Activity
Draw, label, color, and explain the Carbon and Nitrogen cycles on a sheet of paper.
Page figure & 13.15
Due tomorrow

14. Review Questions 13.5 Cycling of Matter
What is the key concept of this unit?
Define the key terms for the water cycle.
What do plants take in and then give out. What do animals take in and give out?
How does the carbon cycle move carbon?
Where is carbon emitted?
Where does the nitrogen cycle take place
What are phosphates released by?