1. Unit 3 Part 2
Food Pyramids

2. 3.2.3 Define Food Pyramid Food Pyramid =
Diagram showing each trophic level as a horizontal bar
The trophic level of an organism is the position it occupies in a food chain
Producers are located on bottom & higher trophic levels are placed on top of each other
Each bar is drawn in proportion to the mass of organisms giving the triangle shape

3. 3.2.2 Why are there fewer organisms at each trophic level?
Less energy available at each level
Fewer organisms can obtain energy to live
Therefore fewer organisms at increasing levels

4. 11. Farmer question about energy efficiency
Wheat would be far more efficient than cattle.
Wheat is a producer and producers contain more energy than primary consumers (like cows) as is seen in the food pyramid. The energy flow diagram shows that each trophic level loses energy as heat.
Farmers would have many other real concerns. Price, growing conditions, markets etc.

5. Biological Amplification 3.2.1
Increase in concentration of toxic fat-soluble chemicals in organisms at successively higher trophic levels of a grazing food chain or food web because of the consumption of organisms at lower trophic levels.

6. 3.2.1 How do food pyramids help explain DDT Biological amplification?
DDT is fat soluble and stays in an animals fat. (compare to alcohol)
Higher order organisms eat such large numbers of lower order organisms. A small amount in a frog becomes a large in a hawk that eats 100 frogs.

8. 3.2.4 Effect on ecosystem with the introduction of new species
In 1997, a pack of 5 coyotes walked across the Strait of Bell Isle.
People wanted to shoot them, however, fish and wildlife did not allow this.
What impact did this have on the Newfoundland ecosystem?