1. Food Chains and Food Webs

2. Producer
Consumer
Herbivore
Carnivore
Omnivore
Predator
Prey
Habitat
Food Chain
Food Web

3. Design questions where each of the preceding key words is the answer
Design questions where each of the preceding key words is the answer. You have 7 minutes. Then swap with someone on our lab bench.

4. Food Chain / Food Web Revision
What do the arrows represent in a food chain?
Flow of energy (food chains are sometimes called energy-transfer chains)
What is the difference between a food chain and a food web?
Food chains show what eats what in a community; food webs show food chains for an entire ecosystem
Label the following food chain using all of your fancy vocabulary:
grass → gazelle → cheetah 4

5. 5

6. Copy the following food chains into your books and then answer the questions on the next slide
Hawk Fox Owl Human Chicken Mouse Chicken Wheat Wheat Berries

7. Combine the three food chains to form a food web
Name two producers and two herbivores
Name a secondary consumer
List two predator-prey relationships
Explain how a fox is a well-adapted carnivore
Imagine that a disease has killed off some of the mice. What affect would this have on:
the owls?
the chickens?

8. Copy the following food web and answer the questions on the next slide
sea bird
starfish
crab
dog whelk
barnacle
limpet
mussel
small algae
SEA SHORE FOOD WEB

9. How many primary consumers are there?
How many secondary consumers are there?
Draw a food chain with 5 links from the food web
Suppose all the starfish died from pollution. Explain what would happen to the number of:
mussels?
small algae?
A fishing village nearby captures most of the crabs from the food web. Explain what affect this would have on the numbers of barnacles.

10. Biology for You Page 323 Questions 1, 2, 3

12. Homework Complete the worksheet for next lesson (Thursday)

13. Pyramids of Numbers
Food chains and food webs can show the feeding relationships in a community.
But they do NOT tell us how many living organisms are involved.
Scientists often represent the numbers in a food chain using a pyramid of numbers

14. oak leaves (600) caterpillars (100) shrews (10) owl (1)
The area of each box in a pyramid of numbers shows how many living things there are at each stage of a food chain.
Always start with the producer at the bottom of your pyramid
Draw a pyramid of numbers for this food chain

15. owl
shrews
caterpillars
oak leaves
But be careful...pyramids of numbers do NOT always have this ‘pyramid’ shape...

16. oak tree caterpillars blackbirds buzzard
Draw a pyramid of numbers for this food chain
buzzard
blackbirds
caterpillars
oak tree

17. rose bush greenfly ladybirds parasites
Draw a pyramid of numbers for this food chain
parasites
ladybirds
greenfly
rose bush

19. Quick Recap

20. Complete the GCSE Worksheet