1. Lets remember

2. Ask students what this is
Ask students what this is?? (food web) can they write on their white boards one food chain?
Zooplankton
Algae

3. Questions on white boards
1. What will happen to the number of clown fish if the sharks become vegetarian?
2. What effect will this have on the number of zooplankton?
3. What will happen to the Blue Regal fish if a disease wipes out the small invertebrates.
Answer questions on white boards one at a time

4. Key word for today?? Peek A Boo
The picture reveals itself on each click, a small amount at a time. The key word is pyramid get them to write on their white boards as soon as they know they can guess continuously with each reveal. Spelling test too

5. Pyramids of Number
Food chains and food webs show the feeding relationships in a community. But they do not tell us how many living organisms are involved.
It takes many plants to feed a herbivore, and many herbivores to feed one carnivore.

6. Pyramids of Number
The population of each organism in a food chain can be shown in a sort of bar chart called a pyramid of numbers. The more organisms there are, the wider the bar. The producer in the food chain always goes at the bottom of the pyramid of numbers

7. Pyramids of Number Think about this food chain:
clover → snail → thrush → hawk
Clover is a plant and it is the producer in this food chain. Its bar goes at the bottom of the pyramid

8. Food Chain Pyramid of Numbers

9. Pyramids of Number
Energy is lost to the surroundings as we go from one level to the next, so there are fewer organisms at each level in this food chain.
A lot of clover is needed to support the snail population. A thrush eats lots of snails, and a hawk eats lots of thrushes, so the population of hawks is very small

10. Other pyramid shapes
Sometimes the pyramid of numbers doesn't look like a pyramid at all.
This could happen if the producer is a large plant such as a tree, or if one of the animals is very small.
Remember, though, that whatever the situation, the producer still goes at the bottom of the pyramid

11. Food Chain Pyramid of Numbers

12. Food Chain Pyramid of Numbers

13. On the coral reef, there are 25 great white sharks.
25 sharks feed on 1,100 clown fish.
The clown fish feed on 15,000 algae.
Can you draw a pyramid of numbers to show this food chain? Use a scale of 1 mm for each 100 organisms to draw the pyramid to scale.
Here is a food chain students draw a pyramid using sale 1mm for every 100 organism

14. Question time
Examination question