Food Chains and Food Webs What's for dinner?"

Food Chains §A food chain is the sequence of who eats what in a ecosystem.

Food Chains §A food chain starts with an energy source. l The sun l Deep sea vents §In our woods, what was the primary energy source? CD

Food Chains §The 1rst link in the chain is an organism that makes its own food from the energy source. l Usually photosynthesis §These are called Primary Producers l Or Autotrophs.

Food Chains §In our woods, what are the Autotrophs? CD §How ‘bout the pond, what are the Primary Producers? CD

Food Chains §Next come organisms called primary consumers. l These are the organisms that eat the autotrophs. §Organisms that eat plants are called herbivores. l An example is a bunny that eats grass

Food Chains §Next link in the chain are the animals that eat herbivores. §These are called secondary consumers. l an example is a snake that eat bunnies.

Food Chains §These animals (the secondary consumers) are eaten by larger predators called tertiary consumers. l For example, owls eat snakes...

Check out these food chains.

Food Chains §Primary producers are autotrophs. §Primary consumers are herbivores (plant-eaters). l Eat secondary consumers. §Secondary consumers are carnivores (meat-eaters) or omnivores (animals that eat both animals and plants). l Eat secondary consumers. §Tertiary consumers are carnivores or omnivores l Eat secondary consumers. §Quaternary consumers are carnivores or omnivores l Eat tertiary consumers.

Food Chains §The arrows in a food chain show the flow of energy, from the source to a top predator. As the energy flows from organism to organism, energy is lost at each step.

Food Chains §A network of many food chains is called a food web.

More Players in a Food Web §When any organism dies, l It is eaten by detrivores (worms, maggots,crabs) l It is broken down by decomposers (bacteria, fungi)

Food Webs