1. Get out homework for signature (Monday’s and Tuesday’s)
Sponge: Set up Cornell Notes on pg. 37
Topic: 4.2 Food Chains and Webs
Essential Question: Draw three food chains, each with at least 3 linkages (4 organisms)-words only
BIOZONE: P ,174
4.2 Food Chains and webs
EQ: Draw three food chains, each with at least 3 linkages- words only
Key Vocabulary:
Food Chains
Food Webs
Trophic Levels:
Primary/Secondary/Tertiary/
Quaternary Consumer
Text: P
Get out homework for signature
(Monday’s and Tuesday’s)

2. P. 36 Trophic Level Pyramid In class: Construct a food web
Build-Your-Own Food Web

3. Understanding
Most ecosystems rely on a supply of energy from sunlight

4. The Importance of Sunlight
All life you see around you on Earth’s surface relies either directly or indirectly on sunlight

5. Understanding
Light energy is converted to chemical energy in carbon compounds by photosynthesis

6. The role of photosynthesis
Remember photosynthesis:
Takes simple inorganic CO₂ and convert it into energy-rich sugar C₆H₁₂O₆
Light energy from sun is being converted into chemical energy (food)

7. The role of photosynthesis
Chemical energy refers to the fact that organic compounds such as carbs, proteins, and lipids are rich in energy
Can be measured by calories or kilocalories
One way to release the chemical energy from organic compounds is to digest the food

8. Understanding
Chemical energy in carbon compounds flows through food chains by means of feeding

9. Food Chains
By feeding on producers, consumers can utilize the chemical energy to grow and stay healthy

10. Food Chains
A food chain is a model that shows a sequence of feeding relationships and energy flow between species
A food chain follows the connection between one producer and a single chain of consumers within an ecosystem.
DESERT COTTONTAIL
GRAMA GRASS
HARRIS’S HAWK
*The direction of the arrow shows the direction of energy flow

11. Trophic levels refer to an organism’s position in a food chain.
Classify organisms by their feeding relationships with the other organisms in the same ecosystem
T5= Quaternary Consumer
T4= Tertiary Consumer
T3= Secondary Consumers
T2= Primary Consumers herbivores
T1= Primary Producers plants
……C a r n i v o r e s…….
Draw on top of P. 36- include examples

12. Understanding
Most species occupy different trophic levels in multiple food chains

13. Organisms can fit into more than one tropic level!
Ex: A common seal is in T3 when it feeds on Grey Mullet
But will be in T4 when it feeds on lobster T4 T3 T3 T2 T2 T1 T1

14. Understanding
A food web shows all the possible food chains in a community

15. A food web emphasizes complicated feeding relationships and energy flow in an ecosystem.
An interconnecting series of food chains.
Since organisms usually eat more than one type of food, a simple food chain does not tell the whole story
ENERGY

16. Arctic Marine Food Web

17. Food Webs m7s

18. Understanding
Energy losses between trophic levels restrict the length of food chains and the biomass of higher trophic levels

19. Energy Levels in Trophic levels
The number of levels is limited by how much energy enters the ecosystem
Energy is lost at each level
So the # of organisms in the chain as well as the quantity of light available at the beginning will determine how long the chain is

20. Determining an organism’s tropic level
In order to determine the tropic level of each organism start with the producer.
Remember: some organisms occupy more than one trophic level or take their food from multiple trophic levels
Algae mosquito larva dragonfly larva fish raccoon
Algae (T1) mosquito larva (T2) dragonfly larva (T3) fish (T4)raccoon (T5)

21. In Class Practice: Construct a Food Web
Algae (plant) is eaten by the mayfly larva
Leaf debris is eaten by the caddis fly larva and the blackfly larva
The mayfly larva, caddis fly larva, and the blackfly larva are eaten by juvenile trout (fish)
The juvenile trout is eaten by the kingfisher (bird)
The mayfly larva is also eaten by the sculpin (fish) and the stonefly larva, all of which are eaten by adult trout
Please include labels to indicate the tropic level of each organism (T 1-5)
Middle of p. 36
Just use words and arrows

22. T3/

23. All trophic levels must be labeled (T1/T2 etc.) Must have pictures
On the bottom p. 36: Construct a food web containing up to 10 organisms
All trophic levels must be labeled (T1/T2 etc.)
Remember: some organisms occupy more than one trophic level or take their food from multiple trophic levels
Must have pictures