1. Energy Pyramids
GLE Describe how matter and energy are transferred through an ecosystem.

2. TCAP Practice Question

3. Answer D
Decomposers help “recycle” the dead organism’s matter back into the soil.
Plants absorb nutrients from the soil.
Plants are primary producers.

4. Energy Review What kind of energy comes from the sun?
What kind of energy is stored in producers?
What kind of energy creates heat loss?

5. Answers Light energy- Radiant energy Chemical energy
Kinetic energy- Mechanical

7. Trophic Levels?
The feeding positions in an energy pyramid, food chain, or food web are called trophic levels. The different trophic levels are defined below.
Trophic Level
Where It Gets Food
Example
1st Trophic Level: Producer
Makes its own food (Autotroph)
Plants make food
2nd Trophic Level: Primary Consumer
Consumes producers (Heterotroph)
Mice eat plant seeds
3rd Trophic Level: Secondary Consumer
Consumes primary consumers (Heterotroph)
Snakes eat mice
4th Trophic Level: Tertiary Consumer
Consumes secondary consumers (Heterotroph)
Hawks eat snakes

9. Check for Understanding
Define Autotrophs.
Define Heterotrophs.

10. Answers Autotrophs- Organisms that make their own food.
Another word for producers.
Heterotrophs- Organisms that cannot make their own food.
Another word for consumers.

11. Video Clip
(3:34)

12. Energy Pyramid
An energy pyramid is a diagram in the shape of a pyramid.
It shows how energy moves from one trophic (feeding) level to another.
Energy moves from the bottom level to the top level.

13. Check for Understanding
What is the name of a diagram that shows how much energy moves from one feeding level to another?

14. Answer
Energy Pyramid

15. Check for Understanding
Which sentence is true about energy pyramids?
A. Energy moves from the top level to the bottom level.
B. Energy moves from the bottom level to the top level.

16. Answer B.

17. Where is the most energy?
In an energy pyramid, the most energy is available at the producer level of the pyramid.

18. Check for Understanding
Which level has the most energy?
Top or bottom?
Producers or consumers?

19. Answer
The most energy is at the bottom level, or with the producers.

20. Higher Trophic Levels
The higher the level on the energy pyramid, the less energy that is available.

21. Check for Understanding
The higher the level on the pyramid, the ________________ energy available.
(more or less)

22. Answer
There is less energy the higher the level.

23. How much energy?
As you move up the pyramid, each level has 10% of the original energy available from the previous level.

24. Check for Understanding
What percentage of the energy of one trophic level is consumed at the next level up?

25. Only 10% of the energy from one level moves on to the next level.

27. Math Break
If producers receive 1,000kcal of energy from the sun, what would the tertiary consumers in that energy pyramid receive?
100,000 kcal
100 kcal
10 kcal
1 kcal
0.1 kcal
0.01 kcal

28. Answer Tertiary means 3rd Level consumer so
Producers starts with 1,000
So 1st level would have 100
2nd level would have 10
3rd level would have 1 kcal

30. What percentage of energy is lost as the trophic level increases?

31. Energy Conservation Review
So where did the remaining 90% of the energy go???
Law of Conservation of Energy says…
Most energy is changed into wasted energy called ________________

32. Check for Understanding
If only 10% of the energy moves up the trophic levels, what happens to the other 90%?

33. Answer
Most of the other remaining 90% of the energy is released into the ecosystem as heat energy.
(However some of the energy could be released as feces, bones/hair that can’t be digested, or even for growth and babies)

34. Critical Thinking
Energy pyramids usually have only three or four levels, never more than five. Why?

35. Answer
By the time 90% of the energy is lost at each level, there is very little energy left for a fifth level organism.
There’s not enough energy to support a sixth level.

36. Music Video
(2:45)

37. Biomass
Energy pyramids also show how much biomass there is at each level.
Biomass refers to the number of organisms and their total mass.
There are more producers in an ecosystem than top level carnivores.

38. Check for Understanding
Other than energy amounts at each level, what else can energy pyramids be used to diagram?
Define biomass.
Which type of organisms has a larger population in an ecosystem?

39. Answers Amount of biomass at each level.
Biomass is the total amount of matter(mass) at each level or the number of organisms.
Producers have the largest populations in an ecosystem.

40. Blue jay

41. Check for Understanding
How many secondary consumers does it take to support this food chain?

42. Answer
Secondary consumers are the perch.
100 is how many are needed.

43. Important Concept
Why are there usually just a few organisms at the top of an energy pyramid? 

44. Answer
So much energy is lost from one level to the next, that the energy still available at the top level can only support a few organisms.

45. Summary Energy pyramids show energy available at each trophic level.
There are more organisms at the bottom of the pyramid compared to the number at the top.
There is more energy at the bottom of the pyramid than at the top.
Only 10% of the energy is carried to the next level
90% of the energy at each level leaves the food chain

46. Ticket Out the Door Label your paper- Name, Date, Block
Number your paper – Don’t skip lines 1. 2. 3.
Multiple Choice Questions.
Use your hand to keep your answers covered.

47. Question 1

48. Question 2

49. Question 3