1. Lesson 3: Nutrient cycling (Carbon and water cycles), carbon source and sink

2. Carbon CycleNitrogen CycleWater Cycle Nutrient Cycles A cycle has no beginning and no end

3. Comparing PS and CR CO 2 and H 2 O C 6 H 12 O 6 and O 2 CO 2 and H 2 O yesYES no yes no yesno

4. The Carbon cycle- All living things contain carbon The carbon cycle is all about how two complementary processes: cellular respiration and photosynthesis

5. Carbon sources = processes emit more carbon than they can absorb Examples of carbon sources Examples of carbon sinks Animals: biotic carbon sources that release CO 2 by cellular respiration Fossil fuels, oceans, soil, atmosphere: abiotic carbon sinks Carbon sinks = processes absorb more carbon than they can give off What can be both a carbon source and sink? Plants: take in CO 2 by PS but also release CO 2 by CR

6. Water cycle

7. 3) Precipitation: From clouds, the water may fall as rain, hail, snow 1) Evaporation: The Sun’s heat water from lakes, rivers, streams, puddles, oceans into a gas, called water vapour 2) Condensation: As water vapour cools, it condenses to form clouds.

8. Water cycle (cont.) Water that hits the ground become: Run-Off water: Water that hits the ground and flows into streams or rivers. Ground water: water might seep into the soil (ground water). This water may flow into oceans or wetlands. Some of the ground water flows into aquifers (large underground lakes). Some of the surface water or ground water is taken up by plants and animals.

9. Nitrogen cycle (after passport activity)