Presentation on theme: "1. Make a list of five foods that you like to eat. Indicate whether the food comes from a plant (producer) or an animal (consumer). 2. Like many birds,"— Presentation transcript:
1. Make a list of five foods that you like to eat. Indicate whether the food comes from a plant (producer) or an animal (consumer). 2. Like many birds, chickens eat grains, which are seeds. Where do seeds come from? 3. Meat comes from beef cattle. What do cattle eat? 4. Construct a diagram showing how one of your favorite foods obtains its energy. Include as many levels as you can.
3–2Energy Flow A.Producers 1.Energy From the Sun 2.Life Without Light B.Consumers C.Feeding Relationships 1.Food Chains 2.Food Webs 3.Trophic Levels D.Ecological Pyramids 1.Energy Pyramid 2.Biomass Pyramid 3.Pyramid of Numbers
ENERGY! Ch. 4, Sec. 2
Energy Flow All living things need energy. Where does it come from?
Primary Producers Organisms that make their own food –from sunlight. –or from inorganic chemicals. Also called Autotrophs. (self-feeder)
Energy from sun is captured through photosynthesis. (plants) CO 2 + H 2 O ------ O 2 + C 6 H 12 O 6 Energy from inorganic molecules is released by chemosynthesis. (primitive bacteria - archaebacteria)
Consumers Organisms that get energy from eating other organisms. (energy is stored in C-C bonds) Also called heterotrophs Ex: bears, deer, mushrooms, humans
Categories of Consumers Herbivores: eat plants. Carnivores: eat animals. Omnivores: eat both plants and animals. Detritivores: eat dead plants and animals. (vultures) Decomposers: breaks down organic matter. (worms, bacteria, etc.)
Energy flows through an ecosystem IN ONE DIRECTION! Sun----> autotrophs-----> heterotrophs. (Sun----> producers-----> consumers)
dark arrows = energy white arrows = nutrients (matter) http://www.marietta.edu/~biol/102/ecosystem.html#Energyflowthroughtheecosystem3
Food Chain: A series of steps in which organisms transfer energy by eating and being eaten. Food Web: Feeding relationships in an ecosystem form a network of complex interactions.
Each step in a chain or web is called a trophic level. Producers are always the first trophic level. Consumers are always second, third, or higher trophic level.
Energy Pyramid Shows the relative amount of energy available at each trophic level. Only about 10% of the energy at one level is available for the next level. The rest of the energy escapes as HEAT or is used for life processes.
To summarize: 1. The ultimate source of energy (for most ecosystems) is the sun 2. The ultimate fate of energy in ecosystems is for it to be lost as heat. 3. Energy and nutrients are passed from organism to organism through the food chain as one organism eats another. 4. Decomposers remove the last energy from the remains of organisms. 5. Inorganic nutrients are cycled, energy is not.
Now draw a food web. 1.Connect organisms with lines showing the flow of energy between trophic levels. 2.Include and LABEL the following: carnivoresprimary consumers herbivoressecondary consumers omnivorestertiary consumers producers consumers autotrophs heterotrophs 3. The most accurate and complex web wins!