1. Unit 2: The Biosphere and Energy Flow

2. Biosphere & Ecosystem
Biosphere: Organisms and their environments (Includes living and dead organic matter)
Ecosystem: A community of organisms (biotic/ living things) and their nonliving (abiotic) environment (what we learned about in Unit 1)
An ecosystem is a smaller part of the overall biosphere

4. I. Energy
A. All organisms need energy to carry out bodily functions like growing, moving around, breathing, keeping our blood circulating, etc.
-The ultimate source of energy for life on earth is the sun.
-Energy is the ability to cause change.

5. II. How Organisms Obtain Energy
Autotrophs: The producers.
Producers turn light energy from the sun into food through a process called photosynthesis.
Ex: Trees, plants, algae.

6. Quick Questions (CFU) What provides energy for life on earth? -the sun
What is energy?
-the ability to cause change
Is a producer and an autotroph the same thing?
-yes
What is an example of a producer?
-a plant

7. III. Heterotrophs Heterotrophs: The consumers.
A consumer can’t make it’s own food so it has to eat other organisms.
Ex: Lions, Humans, Rabbits.

8. IV. Examples of heterotrophs:
1. Herbivore-eats only plants (autotrophs).
Ex: Rabbits
2. Carnivore-eats only animals (heterotrophs).
Ex: Lions
3. Omnivore-eats plants and animals.
Ex: Humans
4. Scavenger-eats dead animals and garbage.
Ex: Vultures
5. Decomposer-breaks down dead or dying material.
Ex: Bacteria, fungi

9. Questions (CFU) What is a consumer?
-an organism that cannot make its own food.
What is an example of a consumer?
-humans
Is a consumer the same thing as a heterotroph?
-yes

10. What kind of heterotroph is this?
-carnivore

11. What kind of heterotroph is this?
-decomposer

12. What kind of heterotroph is this?
-herbivore

13. What kind of heterotroph is this?
-scavenger

14. Most Humans:
Omnivores

15. V. Flow of Matter and Energy
Energy in a Food Chain
The arrows in a food chain or food web show the transfer of energy from one organism to another.
B. Food chain - a model that shows how matter and energy moves through an ecosystem.
berries → mice → black bear

16. VI. Flow of Matter and Energy in Ecosystems
Food Web-a model which shows all possible feeding relationships at each trophic level in a community.
***A food web is more realistic than a food chain because organisms depend on more than one other species for food.

17. VII Trophic Levels
In this class, we will think of these food webs in _levels_________.
Level 1: Producers (plants)
Level 2: Primary Consumers (who eat producers) Ex: Caterpillar, Giraffe
Level 3: Secondary Consumers (who eat Primary Consumers) Ex: Large cats
Level 4: Tertiary Consumers (who eat Secondary Consumers) Ex: Hawk

18. Third-order heterotrophs Second-order heterotrophs
Autotrophs
Third-order heterotrophs
Second-order heterotrophs
First-order heterotrophs
Decomposers

19. In your notes write examples for the following:
1. A producer:
A Tree, Algae, Grass, Plants
2. A primary consumer:
Caterpillar, deer, antelope, cow
3. A secondary consumer:
Lions (feed on antelope, which feed on plants)
Seeds (producer) → Mice → Snakes
4. A tertiary consumer:
Seeds (producer) → mice → snakes → Eagles

20. II. Flow of Matter and Energy
-Each organism in a food chain is a feeding step, or trophic level in the movement of matter and energy.
-Only 10% of energy is passed up each trophic level!!! (Rule of 10)
-Because so much energy is lost at each trophic level, there can only be 3-4 steps in a food chain.

21. You will now practice with these terms with the worksheet provided
1. Heterotroph
2. Autotroph
3. Heterotroph
4. Heterotroph
5. Autotroph
6. Heterotroph
7. Heterotroph
8. Autotroph
9. Autotroph
10. Heterotroph

22. More Answers: 1. Decomposer 2. Herbivore 3. Omnivore 4. Carnivore
6. Scavenger or Omnivore
7. Decomposer
8. Carnivore
9. Herbivore
10. Scavenger

23. 11 and 12: Producers → Primary Consumer → secondary consumer → tertiary consumer

24. 4.2.A.a Illustrate and describe the flow of energy within a food web

25. Example Food Chain:

26. Example Food Web Chihuahuan raven
Honey mesquite (pods eaten by beetles)
Pronghorn antelope
Example
Food Web
Gambel quail
Jackrabbit
Desert tortoise
Coyote
(top carnivore)
Prickly pear cactus
Long-tail weasel
Kangaroo rat (seed eater)
Roadrunner
Mojave rattlesnake
Mexican whiptail lizard
Red spotted toad
ants
Texas horned lizard

27. Questions (fill the answers on WS #2)
What does flow mean?
-to move
Energy flows from _______ to _______ in an ecosystem.
-Energy flows from producer to consumer in an ecosystem.
What is a food chain?
-a model that shows how energy flows in an ecosystem.
What is a food web?
-a model which shows all the feeding relationships in an ecosystem.
Which is more realistic, a food web or a food chain?
-a food web is more realistic than a food chain b/c is shows all possible feeding relationships.
What is a trophic level? -a feeding step.
How much energy can be passed up each trophic level? -10%
Why can there only be 3-4 trophic levels?
-There can only be 3-4 trophic levels b/c only 10% of the energy is passed up each level, which means that after 3 or 4 levels, energy will run out.

28. Food Web Example #2 What are the producers? Algae and Plants
How can you tell?
Are at the bottom of food webs; are green
What three organisms does the fish eat?
Annelids, Mollusks, and Arthropods
What gives the birds of prey its energy?
Mammals and Birds
What are Bacteria and fungi known as?
Decomposers
What do the Bacteria and fungi do?
Breakdown dead organisms
Where are the plants getting inorganic nutrients from?
Bacteria and fungi
What are the two top carnivores?
Birds of prey and Humans

29. Answers to WS #3 1. Produce own food through photosynthesis.
2. Eat other organisms for food.
3. Eat other organisms for food.
4. Break down dead material for energy.
5. 10% is passed up each level.
6. They are using it for life processes such as moving and breathing and some energy is lost as heat as it is transferred to different trophic levels.

30. Food Webs:
1. Phytoplankton
2. Smaller toothed whales
3. Leopard Seals
4. Krill
5. Phytoplankton and zooplankton
6. other birds, fish, penguins
7. penguins, leopard seals, zooplankton, baleen whales, elephant seals

31. 1. Which organisms are the top carnivores
1. Which organisms are the top carnivores? Foxes, hawks and owls, snakes.
2. snakes
3. rabbits, squirrels, mice, seed-eating birds
4. Plants
5. rabbits, squirrels, mice, seed-eating birds

32. WWBAT explain why there are generally more producers than consumers in an energy pyramid.
WWBAT explain how energy distribution will change due to changes in the food web.
The last couple of days we have learned about the terminology of unit 2 and all about food webs. Today we are learning about energy pyramids.

33. A. Types of Food Pyramids:
1. Ecological Pyramids-a model which shows how energy flows through an ecosystem.
Pyramid of Energy
-Pyramid of Energy-shows how energy decreases at each trophic level. Only 10% of the energy is passed up each level!
Heat
0.1% Consumers
Heat
1% Consumers
10% Consumers
Heat
100% Producers
Heat
Parasites, scavengers, and decomposers feed at each level.

34. Pyramid of Numbers
-Pyramid of Biomass-
shows the weight at each trophic level. (________ means how many living plants and animals)
Fox (1)
Birds (25)
Biomass
Grasshoppers (250)
Pyramid of Biomass
Grasses (3000)
1 kg of human tissue
10 kg of beef
100 kg of grain
-Pyramid of Numbers -shows the number of organisms eaten by the animal above it on the pyramid.
That means for every 1000 kg of grass only enough biomass is transferred to make 1 kg of human tissue.

35. You will now finish the backs of WS #3!
You will work on the worksheet for 20 minutes and then we will discuss it as a group.
Stay on Task!

36. Dixie Cup Food Pyramid (10 cups)
Use the cups provided to build and label your own food pyramid with the following:
Autotroph OR Heterotroph?
Producers/Primary/Secondary/Tertiary Consumers?
Carnivore/Herbivore/Omnivore?
Percentage of Energy from the Sun?
Example Organism? (A picture would be nice)

37. STOP: You are going for an interview!
You are going for an interview and must become an expert on the following questions in the next 3 minutes.
Row 1 answer questions 1-5
Row 2 answers questions 6-10
Row 3 answers questions 11-14
We will share out our answers in 3 minutes.
Ready, Set, Go!

38. Questions: In your notes answer the following questions:
1. What is the Pyramid of Energy?
-shows how much energy is in each trophic level.
2. Does the amount of energy increase or decrease as you go up each trophic level?
-decrease
3. Why does the amount of energy decrease?
-energy is lost to the environment as heat.
4. How much energy is transferred up each level?
10%
5. What is the Pyramid of Numbers?
-shows how many organisms exist at each trophic level.
6. What is the Pyramid of Biomass?
-shows how much weight exists at each trophic level.

39. 7. What is biomass?
-amount of living material
8. Which trophic level has the most biomass?
The producers or the bottom of the pyramid
9. Which trophic level has the least amount of biomass?
The tertiary consumers
10. Give 2 examples for the organisms living at the lowest tropic level.
Plants, Trees, Algae, Grass
11. Give two examples of organisms at the trophic level that has the most biomass?
The top, the tertiary consumers

40. 12. If all of the producers were removed from a food web, all the ______________ would eventually starve to death.
13. If organism A was organism B’s food, and organism A was removed, the population of organism B would…
12. If tarantulas eat crickets and crickets eat plants, what will happen to the number of plants if all the tarantulas are removed?
Consumers
Decrease
Decrease