Warm Up 1. Why can’t a food chain have an infinite number of links? 2. Why aren’t there large numbers of big animals (top consumers) in an ecosystem? 3. Name two processes that recycle water in an ecosystem.

The Water Cycle Condensation Transpiration Precipitation Evaporation Runoff Use this slide to discuss cycle, students don’t need to write down yet

The Water Cycle This slide has all the important processes. Draw a stick-figure diagram on the board for students to copy.

What you should know about the Water Cycle 5 main physical processes: Evaporation (ocean/lake  water vapor) Condensation (water vapor  clouds) Precipitation (clouds  rain/snow) Transpiration (the process of water vapor coming out of plant leaves) Runoff (rivers, streams) You need to be able to draw the water cycle as a network.

Think and be ready to share: 1. What are some forms of carbon found on earth or in the atmosphere? 2. Name two processes that recycle carbon in an ecosystem.

Why is Carbon important? Glucose Required for all organisms on earth Needed to make DNA, proteins, fats, sugars Cell membranes are composed of lipids

The Carbon Cycle Draw a stick-figure example of this slide on the board. Add fossilization and skip detritus. Separate trees burning and burning of fossil fuels.

Photosynthesis and respiration 6CO2 + 6H2O C6H12O6 + 6O2 Respiration C6H12O6 + 6O2 6CO2 + 6H2O sunlight Carbon dioxide Water Sugar Oxygen Carbon dioxide Sugar Oxygen Water

Photosynthesis and Respiration Note how the OUTPUT of photosynthesis is the same as the INPUT of respiration Note how the OUTPUT of respiration is the same as the INPUT of photosynthesis Matter CYCLES back and forth between photosynthesis and respiration.

What happens to plants that aren’t eaten by consumers?

What is the role of decomposers? Small organisms Worms, insects Microorganisms Fungi, bacteria

Decomposers Small organisms (worms, insects) break down waste and dead organisms into smaller parts. Microorganisms (bacteria, fungi) digest the smaller parts into chemical forms that can be used by plants. Ex: CO2

Decomposers in the Carbon Cycle The decomposers take waste and turn it back into a form usable by the producers (CO2). The producers then release the carbon dioxide back into the atmosphere.

What you need to know about the Carbon Cycle The role of… Photosynthesis Respiration Decomposers Combustion, human impact You need to be able to draw the carbon cycle as a network. Let’s practice.

Nitrogen Cycle All living organisms must have nitrogen to live (make DNA and proteins.) Atmospheric nitrogen (N2) cannot be used as a nitrogen source by plants or animals. Nitrogen exists in other chemical forms: Ammonia (NH3) Nitrites (NO2) and Nitrates (NO3) Other molecules in waste (urine, dung, corpses)

Draw a network to summarize: Plants (autotrophs) get their nitrogen from nitrites (NO2) ammonia (NH3) and nitrates (NO3) in the soil. Animals (heterotrophs) get their nitrogen from eating plants and other animals. Some special plants and bacteria can “FIX” atmospheric nitrogen (N2) and turn it into nitrites (NO2) ammonia (NH3) and nitrates (NO3) Some Bacteria can produce atmospheric nitrogen (N2) from ammonia (NH3) Animals produce waste containing molecules with nitrites (NO2) ammonia (NH3) and nitrates (NO3) (urine, corpses, feces) Decomposers can turn the nitrogen in dead organisms into nitrites (NO2) ammonia (NH3) and nitrates (NO3)

The Nitrogen Cycle Nitrites, nitrates

What’s important? You must be able to explain that microscopic decomposers (bacteria, fungi) function in ecosystems to recycle carbon and nitrogen.