Food Chains and Food Webs

1
Food Chains and Food Webs

• From your excellent Science Teachers!!

2
Food Chains
3
Food Chain
Not usually included in food chain.
4
The Sun

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

5
Producers

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

6
Primary Consumers

• Known as Herbivores
• Organisms that eat autotrophs
• Starting here, organisms cannot make their own
  energy.

You mean that I am not top of the food chain?!!
7
Secondary Consumers

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

8
Tertiary Consumer

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

9
Quaternary Consumer

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

10
Scavengers and Decomposers

• 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
• Decomposers break down the left-overs and return
  the nutrients to nature (producers)

11
Position in the food chain

• Some animals can move around in the food chain
• 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.

12
The Arrows

• Indicates where the energy is going TO

13
Trophic 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.
• 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.

14
Pyramid
15
Interdependence

• 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.
• The most important level is the producers, the
  entire chain would not exist without them.

16
Food Webs

• These are several food chains that have been
  combined together.

17
Food Webs

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

18
Humans

• 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.

19
Food Chain Video