Food Chains and Food Webs From your excellent Science Teachers!!

Food Chains

Food Chain Not usually included in food chain.

The Sun Not shown in food chains Not shown in food chains Assumed that it is there Assumed that it is there NEW DISCOVERY: Life can exist without the sun, they live in ocean vents in the deep sea. NEW DISCOVERY: Life can exist without the sun, they live in ocean vents in the deep sea.

Producers Plants make their own food by photosynthesis Plants make their own food by photosynthesis Deep sea vents animals make their own food by chemosynthesis. Deep sea vents animals make their own food by chemosynthesis. First part drawn in food chain, base of the food chain. First part drawn in food chain, base of the food chain. Also called autotrophs Also called autotrophs

Primary Consumers Known as Herbivores Known as Herbivores Organisms that eat autotrophs Organisms that eat autotrophs Starting here, organisms cannot make their own energy. Starting here, organisms cannot make their own energy. You mean that I am not top of the food chain?!!

Secondary Consumers Eat the primary consumers Eat the primary consumers Can be omnivores (eats meat and plants) or carnivores (eats meat only) Can be omnivores (eats meat and plants) or carnivores (eats meat only) Can be the end of the food chain in some cases. Can be the end of the food chain in some cases.

Tertiary Consumer Eat the secondary consumers Eat the secondary consumers Usually Carnivores Usually Carnivores There are not very many in the animal world (as compared to producers) There are not very many in the animal world (as compared to producers) Most food chains that we do will end here Most food chains that we do will end here

Quaternary Consumer Top of the food chain Top of the food chain Always a carnivore Always a carnivore Nothing else eats these animals Nothing else eats these animals

Scavengers and Decomposers Scavengers are a little weird because they eat food left behind, they do not actually kill to eat Scavengers are a little weird because they eat food left behind, they do not actually kill to eat Can fit any part of the food chain Can fit any part of the food chain Decomposers break down the left-overs and return the nutrients to nature (producers) Decomposers break down the left-overs and return the nutrients to nature (producers)

Position in the food chain Some animals can move around in the food chain Some animals can move around in the food chain Exists at different levels Exists at different levels When a bear eats berries it is a primary consumer but when it eats the bad seventh grader it is a tertiary consumer. When a bear eats berries it is a primary consumer but when it eats the bad seventh grader it is a tertiary consumer.

The Arrows Indicates where the energy is going TO Indicates where the energy is going TO

Trophic levels We use a pyramid to show the different levels. We use a pyramid to show the different levels. Plants are always on the bottom, the biggest part. There are many more plants than animals. Plants are always on the bottom, the biggest part. There are many more plants than animals. The levels of the pyramid get smaller as you go up The levels of the pyramid get smaller as you go up There are less animals in the world that fit in each level as you go up. EX: There are more zebras than lions. There are less animals in the world that fit in each level as you go up. EX: There are more zebras than lions.

Pyramid

Interdependence Each level depends on the next to exist. Each level depends on the next to exist. If one level dies out, the levels above it have to adapt or they will die out too. If one level dies out, the levels above it have to adapt or they will die out too. The most important level is the producers, the entire chain would not exist without them. The most important level is the producers, the entire chain would not exist without them.

Food Webs These are several food chains that have been combined together. These are several food chains that have been combined together.

Food Webs The lines do not form a straight line as food chains do. The lines do not form a straight line as food chains do. Usually has several animals of every trophic level. Usually has several animals of every trophic level. EX: a snake is not the only thing that eats a mouse EX: a snake is not the only thing that eats a mouse Easy to remember because it looks like a spider web. Easy to remember because it looks like a spider web.

Humans Humans are not the top of the food chain every time. Humans are not the top of the food chain every time. We have too many ways to influence the food chain for us to count. We have too many ways to influence the food chain for us to count.

Food Chain Video