1. Ecology Unit: Biogeochemical Cycles Chapter 3.3

2. Biogeochemical Cycles Nutrients are passed between organisms and the environment through biogeochemical cycles. Why do living things need nutrients? What if the nutrient is in short supply? If a nutrient is in short supply, it will limit the organisms growth potential. This is a “limiting nutrient.” 4 Nutrient Cycles: Water, Carbon, Nitrogen, Phosphorus

4. 1.What are the 2 processes that allow water to be released into the air? 2.Water in gas form is turned into liquid form by this process… Water Cycle Questions: Evaporation and transpiration Precipitation

5. CO 2 in Atmosphere CO 2 in Ocean

6. Carbon CycleCarbon Cycle Q uestions: 1.What process takes CO2 from the air? 2.What biotic process releases CO2 into the air? 3.What kind of organisms can do the answer to question #1? Photosynthesis Cellular respiration Plants!

8. Section 3-3 Figure 3-14 The Nitrogen Cycle

9. Nitrogen Cycle Questions 1.Where do plants get their nitrogen from? 2.Where do animals get their nitrogen from? 3.What organisms can “fix” gaseous nitrogen from the air and put it in the soil? 4.What kind of bacteria can put nitrogen back into the air? Nitrifying bacteria Eating plants Bacteria Denitrifying bacteria

11. Phosphorous Cycle 1.Since phosphorous does not enter the atmosphere, how do we get it? 2.Name a VERY important molecule we need it for: Rocks and soil Nucleic acids