1. Food Chains and Ecosystems
4th Grade Life Science
Food Chains and Ecosystems

2. Food Chains All ecosystems contain food chains
Food Chains All ecosystems contain food chains. Each food chain contains both predators and prey.

3. A food chain shows the order in which animals eat plants and other animals. Each part of a food chain is a link connected to other links.

4. Food Chains
Food chains show what eats what in order to gain the energy it needs to live.
Food chains use arrows to show what eats what.
Eaten by:
Eaten by:

5. Plants Plants are at the beginning of virtually EVERY food chain
They are PRODUCERS and use sunlight to make sugar in a process called PHOTOSYNTHESIS
These sugars are stored in their leaves, stems, fruits, and roots

6. Review Question #1 Which organism in this food chain is the producer?
A The bunny
B The owl
C The flowers
D The sun

7. Answer Question #1
C The flowers are a producer because they can make their own food using sunlight. Remember, mushrooms are decomposers. They break down the tissues of dead plants and animals.

8. Consumers Animals are consumers.
Some consume plants to get the energy they need to live.
Others consume other animals.

9. Herbivores Herbivores are animals that only eat plants.
Herbivores are found at the beginning of the food chain because they eat the producers (plants)

10. Review Question #2 Which organism in this food chain is the herbivore?
A The bunny
B The owl
C The flowers
D The sun

11. Answer Question #2
A The bunny is an herbivore. It is the only organism in the food chain that is a plant eater.

12. Carnivores Carnivores are animals that eat meat.
Carnivores will also eat animals that eat plants.
They never eat producers and are usually at the top of food chains.

13. Omnivores Omnivores will eat both plants and animals.
Some animals eat both plants and meat.
Most people are omnivores

14. Food Webs
Food webs show how the many different food chains in an ecosystem are connected.

15. Food Web Most organisms eat more the JUST one organism
Food webs are more complex than food chains and involve lots of organisms

16. Review Question #3 A owl B rabbit C deer D black bear
The diagram below shows a food web. Which animal is an omnivore?
A owl
B rabbit
C deer
D black bear

17. Answer Question #3
D The black bear is an omnivore because it eats both berries (plant) and rabbits (meat). The red fox is also an omnivore. The rabbit and deer are herbivores and the owl is a carnivore.

18. Competition
Animals may compete with others in an ecosystem for the same resources.
For example, off the coast of Washington, sea lions and fishermen both want to catch salmon. This leads to competition between the two groups.

19. Review Question #4
The diagram below shows a food chain
Which of following animals might compete with the bird in this food chain?
A deer C lizard
B grasshopper D lion

20. Answer Question #4
C The lizard would compete with the bird because they both eat the same food: insects.

21. Decomposers
Decomposers break down dead and decaying matter, including poop, and return the nutrients to the soil
Bacteria
Mushrooms
Certain Insects
Are ALL examples of DECOMPOSERS

22. Review Question #5 Which of the following organisms is a decomposer?
A Turtle
B Millipede
C Flower
D Spider

23. Answer Question #5
B A millipede is an example of a decomposer. Flowers are producers and turtles eat living things like plants and insects. Spiders are carnivores. They eat bugs.

24. All ecosystems have the same parts: They can be characterized by their
Living Factors
Nonliving Factors

25. The nonliving parts of an ecosystem include:
Nonliving Factors
The nonliving parts of an ecosystem include:
Water Soil
Minerals
Sunlight
Air

26. Living Factors The living parts of an ecosystem.
They include the producers like plants and consumers like herbivores, carnivores, omnivores, and decomposers.

27. Review Question #6
Which of the following choices contains two nonliving factors in an ecosystem?
A air and plants
B animals and water
C plants and animals
D air and water

28. Answer Question #6
D Nonliving factors are things in an ecosystem that are NOT living, like air and water.

29. Adaptation
Animals and plants have special features that allow them to survive well in particular environments.
For example, the thick fur of the polar bear allows it to survive in the Arctic.
An iguana, with no fur, would not survive the harsh Arctic climate.

30. Food webs and ecosystems can be affected by changes in animal populations.
If a disease killed all the birds in this ecosystem, then the population of horseshoe crabs would increase because there are no birds to eat them, and the population of razor clams would decrease because all the horseshoe crabs would be eating them.

31. Review Question #7
What would happen right away to the rat population if all the coyotes were shot by hunters?
A their population would increase
B their population would decrease
C there would be no change in their population
D they would all get sick

32. Answer Question #7
A If all the coyotes were gone, the rats would have no predators and their population would increase.

33. Plants and animals depend on each other
Plants need animals, like birds and insects for pollination.

34. Plants and animals depend on each other
Plants also need animals to disperse their seeds. Animals can eat the seeds and pass them out later in their waste, or seeds might stick to an animal’s body

35. Plants and animals depend on each other
Animals depend on plants for food and for shelter
© Alex Wild 2008

36. Review Question #8
Peach trees have sweet-smelling blossoms. Why do the flowers have such a sweet smell?
A to create nice-smelling flower arrangements
B to attract bees for pollination
C to scare away predators
D to protect the tree from disease

37. Answer Question #8
B Plants depend on animals for pollination. Bees are great pollinators. The sweet smell of the flowers and fruits attracts the bees to the tree.

38. Microorganisms
Microorganisms are organisms that you need a microscope to see.
They can HELP you and HURT you
Helpful: Harmful:
1. Bacteria in yogurt 1. Viruses cause illnesses
2. Fungi to make antibiotics 2. Bacteria can spoil food
3. Bacteria that decompose 3. Mold can grow on
dead matter food, like bread,
and ruin it