Food Webs Food Chains Learning GoalsSuccess Criteria Understand

Food Webs & Food Chains

Learning Goals/Success Criteria • Understand interaction between organisms in food chains and food webs (Producers, primary consumer secondary consumer. . . ) • Explain trophic levels and the 10% rule • Draw energy pyramids to show transfer of biomass through food chains

Check for Understanding • Draw a diagram to show the CARBON CYCLE!

So So Answer

Awesome Answer!

Food Chains & Food webs • One of the most important interactions between species is the feeding relationship Producer organisms produce their own food Herbivores Plant-eating consumers Carnivores Meat-eating consumers

Omnivores Meat & Plant eating consumers Scavengers Eat dead remains of animals Decomposers Break down animal body and waste

Food chains • Food Chain – shows a sequence of feeding from one organism to another

Trophic Levels • Ecologists refer to the trophic levels to describe the feeding position of an organism on a food chain. • Organisms are defined by how they gain energy

Trophic Levels Biomass: the total mass of living organisms in a group or area • As you go up a trophic level, energy is being passed through the ecosystem. However, energy is lost in each level of the food chain. Trophic Efficiency: • 90% of the energy is used by the organism for life functions (growth) and is also lost as heat • Only 10% of the energy gets transferred to a higher trophic level (10 % RULE) • This is why most food chains only have 4 -5 levels

Energy Pyramids • Shows the transfer of energy from one trophic level to the next Biomass

Tropic Levels – Transfer of Energy Grasshopper Mouse Snake Eagle Grass Organism Energy Available Energy Used in Metabolism Energy Stored Grass 50000 _____k. J 45000 __________k. J Grasshopper 5000 _____k. J 4500 __________k. J Mouse 500 __________k. J 450 _____k. J 50 Snake 50 _____k. J 45 __________k. J Learning Check! Draw a Food Pyramid to Represent transfer of energy through this food chain

Food Webs • Food web – a representation of MANY FOOD CHAINS in a community

Learning Check! • Practice: Create a food web given the following food chains. • Grass caterpillar small bird eagle Grass snail small bird eagle • Grass caterpillar lizard eagle Grass rabbit eagle

Get into groups! • Work on the handout package from Mr T and hand it in AS A GROUP!

Ecology Picture(? )of the Day

Ahh… That’s Better!