1. Flow of Energy in an Ecosystem
Ecology Day 9

2. Food Chain and Web WU: Teacher Image Student Image 44 45 9-25
Flow of Energy
EQ:
Summary
Food Chain and Web
WU:
Teacher Image
Student Image 44 45

3. Warm Up Top of page 44 Define species:
a group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding.
Warm Up Top of page 44

4. Essential Question:
How does energy flow from the sun, through trophic levels, and end as heat?

5. Flow of Energy The main source of energy is the sun
NBpg. 45
Slide 1 of 3
Flow of Energy
The main source of energy is the sun
Autotrophs are plants, some algae and bacteria, that capture energy to produce food.
AKA: Producers
Heterotrophs are organisms that rely on other organisms for their energy and food supply.
AKA: Consumers

6. Omnivore eats plants and animals Carnivore eats animals
NBpg. 45
Slide 2 of 3
Consumers can be:
Herbivore eats plants
Omnivore eats plants and animals
Carnivore eats animals
Detritivores eats dead matter
Interactions within the biosphere produce a web of interdependence between organisms and the environment, which contributes to an ever-changing, or dynamic, biosphere.
The flow of energy goes through a food chain and food web

7. Flow of energy is in ONE DIRECTION
NBpg. 45
Slide 3 of 3
Flow of energy is in ONE DIRECTION
Plants get their energy from the sun (photosynthesis)
Consumers get their energy from their food:
Herbivores 10% of the Plants energy
Primary Consumers 10% of Herbivores energy (1% of Plant energy)
Secondary Consumers 10% of Primary’s (1 % of Herbivore, 0.1% of Plant)
When energy is consumed from food/prey, only 10% of the energy is passed to the consumer/predator

8. Copyright Pearson Prentice Hall
NBpg. 44
Try to draw the images but label them and draw the structure (chain/web)
ARROWS SHOW THE FLOW OF ENERGY
owl
hawk
tree
owl
bug
fox
mouse
bird
mosquito
grasshopper
mouse
grasshopper
chipmunk
deer
grass
grass
rabbit
Copyright Pearson Prentice Hall

9. Identify the above with the picture
Just Checking:
Producers
Autotroph
Consumer
Carnivore
Herbivore
Omnivore
Flow of Energy
In your groups
Identify the above with the picture
owl
snake
fox
rabbit
mouse
frog
Grass-hopper
squirrel
Plant One
Plant Two

10. Ecological Pyramid Assignment
9-26
Ecological Pyramid Assignment
9-26
Ecological Pyramids
Energy
Biomass
Pyramid of Numbers 46 47

11. Ecological Pyramids Textbook pages 72-73
NBpg. 46
Slide 1 of 3
Ecological Pyramids Textbook pages 72-73
Energy Pyramid
Only about 10% of the energy available within one trophic level is transferred to organisms at the next trophic level.
This is because organisms use much of the energy that they consume for life processes (respiration, movement, growth and development…)which is released as HEAT

12. Represents the amount of living organic matter at each trophic level.
NBpg. 46
Slide 2 of 3
Biomass Pyramid
Represents the amount of living organic matter at each trophic level.
Typically the greatest biomass is at the base of the pyramid.
Usually expressed in terms of grams of organic matter per unit area

13. Ecological Pyramids Pyramid of Numbers
NBpg. 46
Slide 3 of 3
Ecological Pyramids
Pyramid of Numbers
Shows the relative number of individual organisms at each trophic level.
This pyramid might not have the traditional pyramid-shape.
1 hawk
6 snakes
12 primary
consumers
200 producers

14. Assignment: Ecological Pyramid 30 Points
Page 47
You will use the pyramids you drew to create your own Ecological Pyramid
It will be 3-sided
Each side will feature one of the following (all 3 will be used; 10 points each)
Draw and label a food web
Energy: Show a food chain with the 10% rule
Pyramid of numbers: Show a food chain
You decide what organisms will be featured on your pyramid
It must be detailed and colored; no white space
Assignment: Ecological Pyramid 30 Points