1. Chapter 3: The Biosphere
Section 3-2: Energy Flow

2. Interest Grabber
Section 3-2
Pass It Along
Energy flows in one direction through an ecosystem, from the sun or inorganic compounds to producers (organisms that can make their own food) through various levels to consumers (organisms that rely on other organisms for food).
Your body gets the energy and materials it needs for growth and repair from the foods you eat.

3. The need for energy… Energy is needed to drive life processes
Example: Ants can lift many times their mass - energy is needed!
You need energy to wake up!
Ecosystems need energy to sustain life.

4. Sunlight is the main energy source for life on Earth.
A. Producers

5. What were examples of producers associated with the food web game?

6. A.1:Energy From the Sun
Photosynthesis: Plants harvesting energy from the sun
Convert CO2 & H2O into Carbohydrates & water (Ch 8)

7. Photosynthetic Organisms
Land
Plants are the primary photosynthetic organisms
Water
Algae or phytoplankton are the main photosynthetic organisms
Some photosynthetic bacteria as well

8. Photosynthetic Bacteria
Photosynthetic bacteria like these are found in tidal flats and salt marshes
They are called cynobacteria and contribute to the oxygen on the earth

9. A-2:Life Without Light: Chemosynthesis
Chemosynthetic bacteria such as these use sulfur in hydrogen sulfide to produce energy rich carbohydrates

10. Chemosynthetic Bacteria
These bacteria live in remote places on the earth
Yellowstone National Park’s hot springs is one such place
Tidal marshes are another

11. Comparison of Photosynthesis & Chemosynthesis

12. Heterotrophs: Obtaining energy from producers
B. Consumers
Heterotrophs: Obtaining energy from producers

13. Heterotrophs Organisms that rely on other organisms for energy needs
Also called consumers

14. What were the heterotrophs associated the food web game?

15. Types of Heterotrophs 1. Herbivores 2. Carnivores 3. Detritivores
4. Decomposers

16. 1. Herbivores
Eat plant material
Examples?

17. 2. Carnivores
Organisms that eat animals
Examples?

18. 3. Omnivores
Organisms that eat both plants and animals
Examples?

19. 4. Detritivores Organisms that feed on plant & animal remains
They eat dead matter - detritus!
Examples?

20. C. Feeding Relationships
Movement of energy through an ecosystem

21. Energy Flow Food - be it plant or animal food - contains energy
Some food contains more energy than others
Energy flows in one direction in an ecosystem

22. Energy Flow

23. Energy flow…..!

24. C-1:Food Chains
Energy is passed along in an ecosystem through food chains
Food chain is a series of steps in which organisms pass energy in the form of food

26. Aquatic Food Chains
Algae/phytoplankton are the basis for the aquatic systems.

27. Pollution: Disruption in Aquatic Food Chains
Biomagnification

28. C-2: Food Webs Complex feeding relationships
Feeding relationships can be quite confusing!
This is a Great Lakes food web!

30. C-3: Trophic Levels
Each step in a food chain is called a trophic level
Produces make up the first level
Consumers make up the 2nd, 3rd etc
Each consumer depends on the trophic level below

31. D. Ecological Pyramids
Representing Energy or the amount of Matter or Numbers in an Ecosystem
3 Types of Pyramids

32. Ecological Pyramids Section 3-2 Energy Pyramid
Shows the relative amount of
energy available at each trophic
level. Organisms use about 10
percent of this
energy for
life processes.
The rest is lost
as heat.
Pyramid of Numbers
Shows the relative
number of individual
organisms at each
trophic level.
Biomass Pyramid
Represents the amount of
living organic matter at each
trophic level. Typically, the
greatest biomass is at the
base of the pyramid.

33. D-1: Energy Pyramid Energy is passed between trophic levels
Organisms use the energy for life functions
Some of the energy is released as heat
10% is passed on to each successive trophic level

34. D-2: Biomass Pyramid
Represents the amount of biomass at each trophic level
Expressed in grams / unit area

35. Biomass Pyramid Enlarged
Notice the change in each successive stage

36. D-3: Pyramid of Numbers
Represents the number of each organism at each trophic level
May be the same or different than an energy of biomass pyramid