3-2 Energy Flow

2. Sunlight is the main energy source for life on Earth. Autotrophs A. Organisms that make their own food. (plants) 1. Producers-organisms that use sunlight to make their food, usually through photosynthesis – plants are producers, and some animals. 2. Sunlight is the main energy source for life on Earth.

3. Consumers A. Heterotrophs-organisms that acquire their energy from outside organisms. Eating producers, also known as consumers. B. Consumers – they consume organic molecules made by other organisms 1. Herbivores – eat producers 2. Carnivores – eat consumers 3. Omnivores – eat both 4. Detritivores – consumers that eat plant and animal remains and other dead matter, The dead matter is called Detritus (ex.Mites, earthworms, snails) 5. Decomposers – organisms that break down and obtain energy from dead organic matter. (bacteria and fungi)

C. Consumer terms 1. Producer- always located on the 1st or bottom level of a food web or food chain. A. 1st level - producers, consumed by herbivores. B. 2nd level – herbivores, consumed by carnivores and omnivores. C. 3rd level - consumed by carnivores or omnivores. Feeding level usually exceeds three levels

2. Food web – the interrelated food chains in an ecosystem. 4. Energy flow A. Trophic levels – shows the position of the organisms in the flow of energy, also the steps in a food chain or food web. 1. Food chain – a single pathway of feeding relationship among organisms that result in energy transfer. 2. Food web – the interrelated food chains in an ecosystem. 3. Energy – Flows in one directions. 4. Nutrients – Recycle through the environment, to be used again. .

Food Chain

Food Web

3. 10% law – only 10% of the energy available within that trophic level is transferred to organisms at the next level.. a. Because organisms use energy, not save it. Lots of it is used to heat their bodies. b. Only 10% gets passed from one organism to the other. 4. Biomass – The total amount of living tissue within a given trophic level. (grams of available food per unit area)

Plants capture approximately 1% of the available light energy from the sun for biomass production by way of photosynthesis. Photosynthesis can be described chemically as: Light Energy + 6C02 + 6H20 = C6H1206 + 602 (1,000 Units of Energy) Herbivores consume approximately 10% of the plant biomass produced in a typical food chain. (100 Units of Energy) Carnivores capture and consume about 10% of the energy stored by the herbivores. (10 Units of Energy)

10% LAW

Food WEB