1. Energy Transfer and Feeding Relationships
“What’s for dinner?”

2. Reminders and Take Notice!
Your lab is due on Monday, March 25. You and your partner will be marked on:
proper arrangement of the write up
completion of the lab in its entirety
Your ability to reflect upon the observations made based on the experiment you carried out
You will have your first quiz on Wed. March 27
Topics include 1. The Earth’s Spheres, 2. Biotic and Abiotic features, and 3. Energy Consumption + Feeding Relationships
In other words, the first three slide shows, omitting adaptation

3. Feeding types
Animals can be grouped in several ways. One way of doing this is based on how animals feed.
Some organisms are producers. Producers make their own food.
Plants produce their own food using
light energy from the Sun. Some types of bacteria can also make their own food by using light or chemical reactions.
Consumers cannot make their own food. They must consume other organisms to get the food that they need.

4. Where does all the Energy in a food chain come from?
Major source of energy for our planet
Provides energy used by green plants to make their own food in the process known as Photosynthesis
Plants provide food for other organisms
Also provides solar energy to generate electricity, light energy and thermal energy to warm the planet and its inhabitants

6. How does the Energy get IN to the Food Chain?
Photosynthesis
Executed by plants
A process by which plants take in the sun’s energy, carbon dioxide and water to produce oxygen and stored energy upon which plants grow and survive
Carbon Dioxide + Water + Sunlight  Sugar (energy) + Oxygen
CO2 + H2O + Sunlight  C6H12O2 + O2
The reason photosynthesis occurs in plants and not animals is because it requires a chemical called chlorophyll

7. How do CONSUMERS USE this energy?
Cellular Respiration
Occurs in animals
A process by which animals take in sugar and oxygen to fuel the body while producing water and carbon dioxide
C6H12O2 + O2  CO2 + H2O + ATP

8. Complementary Processes
The product of one process equals the starting components of the other process

9. Types of Consumers Herbivores: plant eaters (eg. Rabbit) Carnivores:
meat eaters (eg. Fox)
Omnivores:
plant and meat eaters (eg. Bear)

10. Food chains – what eats what?
With the following groups, create a food chain, identifying
each group member as a plant or animal.
**REMEMBER WHAT YOU WERE AND WHERE YOU
FELL IN THE CHAIN.
Arctic 1
Caroline
Emma
Micaela
Tatum
Forest 1
Paul
Tristan
Jacob T.
Luke
Pond 1
Patrick
Tony
Stephen
Arctic 1
Nathan
Nick G.
Hennadiy
Nick R.
Forest 1
Matt
Kyle
Alex
Zach
Pond
Rachel
Tasha
Mandy
Cindy
Arctic 2
Jo-Anna
Holly
Julie
Katie
Forest 2
Karly
Jillian
Melissa
Sarah
Pond 2
Jim
Derek
Keegan
Arctic 2
David
Oliver
Madi
Liv
Forest 2
Alec
Jacob M.
Jacob R.
Jacob B.

11. Food chains A food chain shows what is eaten by what.
Each arrow means ‘eaten by’.
leaf
caterpillar
bird
cat
What does this food chain show?
A leaf is eaten by a caterpillar, which is eaten by a bird, which is eaten by a cat.
Energy is transferred from one organism to another in the direction of the arrow

12. Food chains – activity Green plant Goat Owl Rabbit
Mouse Wild Cat Snake Eagle
Lion Jackal (like a wolf)
Green plant, mouse, wild cat, lion. Green plant, rabbit, jackal, lion. Green plant, goat, jackal, lion. Green plant, mouse, snake, eagle. Green plant, rabbit, wild cat, lion

13. Ranking consumers
A food chain can be used to rank different types of consumers.
human
crayfish
limpet
seaweed
primary
consumer
secondary
consumer
tertiary
consumer
producer
producers – make their own food;
primary consumers – eat producers;
secondary consumers – eat primary consumers;
tertiary consumers – eat secondary consumers.

14. Do animals only eat one species??
Food chains show simple relationships
Food webs show all the feeding relationships in a habitat

15. Which of these organisms are producers?

16. Which ones are Herbivores?

17. Which ones are carnivores?

18. Which ones are omnivores?

19. Build a food web
Nuts Mice Wolf Bear Nuts Deer Wolf Bear Bark Rabbit Wolf Bear Blossoms Insects Birds Red fox Bear Blossoms Bees Bear Bark Rabbit Red fox Bear

20. Food Pyramids
We draw food webs to show how animals’ eating habits are related
We draw pyramids to show how energy (biomass) is passed along from one animal to the next
What shape is a pyramid?
What can the shape tell us about energy at the top?

21. What is Biomass?
The total dry mass of living organisms in a group or area

22. Example:
How do we measure the biomass for field of grass? (producer level on our food chain)
Dry the grass then take the mass of it
= biomass of the grass

23. Biomass tells us how much Energy is available to the next trophic level
Why do we take the water out when we measure biomass???
Example: What has more energy?
Watermelon Bread
The reason why we take the water out when we measure biomass is because the water makes it heavier but doesn't’t tell us how much energy.
Water doesn’t provide energy.

24. Two Types of Pyramids 1) Pyramid of Numbers
Count number of each organism
Not as accurate
Example: 1 oak tree, 10 caterpillars, 2 birds
Blackbird
Caterpillar
Oak Tree

25. Types of Pyramids 2) Pyramid of Biomass
Weigh all the organisms at each stage of the food chain (biomass of producers > consumers)
More accurate to show feeding relationship
Example: even if there is only one oak tree it can have many caterpillars living from it
Blackbird
Caterpillars
Oak Tree

26. Food Pyramids and Energy
Only about 10% of the energy from one level gets passed to the next

27. Reasons why biomass decreases as you go up the pyramid:
Not all of the plant is eaten by herbivores (only eat leaves, not roots)
Not everything eaten is digested (wolf eats a deer, uses meat but fur is waste)
Energy is lost in the form of body heat, used for activity, to carry out life processes

28. Example:
When we eat chicken for dinner we do not get 100% of the energy from it. Why?

29. Eating lower on the food chain wastes less energy
Animals need energy to live, grow and reproduce
Animals get less energy from what they eat if at the top of the food chain
This can explain why there are usually fewer carnivores than herbivores, and fewer herbivores than plants
Eagle
Rabbit
Grass

30. Practice Calculation for Energy Transfer
Calculate the units of energy in each trophic level of the food chain below. Remember that only 10% of the energy gets passed along.
(Starting energy units) x (0.10) = Energy passed along

31. (Starting energy units) x (0.10) = Energy passed along
(2543) x (0.1) = units of energy (grasshoppers)
(254.3) x (0.1) = units of energy (spotted frog)
TRY THE NEXT STEP ON YOUR OWN!

32. (Starting energy units) x (0.10) = Energy passed along
(25.43) X (0.1) = units of energy (red-tailed hawk)

33. Answer:
Hint: Every trophic level you move up in the food chain, you move the decimal over one place to the left (This is 10% of the starting number)
254.3 energy units
25.43 energy units
2.543 energy units