April 4- 8, 2011 4th g LPlans
Lesson Bridge** For this TEKS, reference 4th Grade, Unit 05, Lesson 02 Ecosystem Interactions
TEK’s
4.9 B Describe the flow of energy through food webs, beginning with the Sun, and predict how changes in the ecosystem affect the food
web, such as a fire in a forest.
Key Understandings
• Changes to an ecosystem can affect the flow of energy through food webs.
Performance Indicator(s)
• Using the model of the ecosystem created earlier, select a member to remove from the ecosystem. Interview one of the remaining members
about how this has affected them. Write a news report based on the interview. (4.9B)
Day/Date
Instruction
M April 4
DAY 12
Explore, p. 6-7 of 44
Materials/Notes
Desert Organisms and their Niche cards
(Unit: 5 Lesson: 01)
Today we are going to go back to the
handout: Desert Organisms and their
Niche cards from the last unit and
research how the different organisms
in the desert react with one another.
Explain that interaction occurs when
components of an ecosystem act upon one
another.
To introduce how to use the desert
ecosystem notes to determine feeding
relations, start by modeling feeding
relationships using handout: Feeding
Relationships
Handout: Feeding Relationships (1 per
teacher, transparency) Handout: Food
Chain Gang (1 per group)
Handout: Example of Food Chain Gang (1
per teacher)
The time allotted is up to the teacher. 30
minutes is a suggestion.
Food Chain Gang graphics can be cut out
ahead of time or you can allow your
students to cut them out as they need them.
After time is called, allow each group to
share their food chains. Check to see if their
Model several very simple feeding
relationships Add the sun to the feeding
relationship chain.
Play the Food Chain Gang game.
Explain that everybody’s somebody’s
lunch.
Journal:
Have students put their Food Chains into
their Journals.
food chains are acceptable. Many
combinations exist. Some examples of
desert ecosystem food chains have been
included for the teacher in the handout:
Example Food Chain Gang.
English Language Learners may need to
see many examples before they can create
food chains on their own.
Note that the feeding relationship is very
simple. It is a chain.
MATERIALS:
Say: Let’s look at food chains from a
different angle – let’s look at it from an
energy transfer angle.
Journal: Have students create a Venn
Diagram for the following questions.


large bowl or container
12 ounce cups
small disposable cups
medicine cups
How are plants and animals
alike?
How are they different?
popcorn (or pasta or beans or styrofoam
peanuts or anything that is small and handy)
Handout: Simple Food Web KEY (1 per
teacher)
Handout: Let’s Eat! (1 per teacher)
Handout: Making Connections (as needed)
Handout: Making Connections KEY (1 per
teacher)
(The containers you use can be any type of
container as long as they decrease in size.)
T April 5
STARR Assessment
W April 6
DAY 13
Explain, Steps 1-11, p. 7 of 44
Look at our food chains in our journals
Handout: Making Connections (optional)
Explain that in ecosystems feeding
relationships can be very complex
Journal:
 Choose just one plant to narrow
their search.
 Write grasses, trees and shrubs at
the bottom of their Journal look



Th April 7
DAY 14 Explain, Steps 12-22, p. 8-9 of 44
Handout: Simple Food Web KEY
through their desert organism cards
or think of other animals that eat
grasses, seeds, and shrubs
pull out the cards for the caterpillar
and the pocket mouse add these
above the “grasses, seeds, and
shrubs” label


MISCONCEPTIONS:
When an animal eats food (plants or other
animals), one hundred percent of the energy in
that animal is transferred to the new organism.
add arrows
add two carnivores, the tarantula
and the snake, above the labels for
caterpillar and Pocket Mouse and
then add arrows.
Take out your Journals. We will pick up where
we left off yesterday.

The teacher needs to model building the food
web for their students. Place a producer at the
bottom and work your way to the top level
consumers –carnivores who eat carnivores.
You may choose any of the organisms. The
lesson suggests one path that you may choose
to follow. If your class wants to go another
direction, seize the moment! Be creative.
add the tarantula hawk wasp and
coyote to their labels
connect the food to the new
connect the food to the new
consumers using arrows
Have students turn back to their notes on
coyotes.
Coyote “extra” arrows are indicated in RED
in the handout: Simple Food Web KEY.
Road runner arrows are in BLUE in the
handout: Simple Food Web KEY. English
Language Learners and special needs
students may need extra help.
Handout: Making Connections is provided
in case your students need additional
instruction before they manipulate the data
on their own. Use it if you need to, the
choice is yours.
What else do coyotes eat besides snakes?
(They eat insects, reptiles, and mice.)
Do we have any of those of the diagram?
(Yes.)
How are we going to show what else the
coyote eats? (Lead the students to
acknowledge that adding more arrows will
show all the foods that coyotes like to eat.)
MISCONCEPTIONS:
All large animals are carnivores. A better
indicator of the classification of the animal is
what the animal eats or how their teeth are
formed than their size.
A species high on the food web is a predator
to everything below it.
Say: Now, let’s go one step further. Let’s
add the road runner into our diagram.
look at all the arrows. We call this diagram a
food web.
Why can’t it be called a food chain?
(Because it is not one organism linked to
another. It is not a simple series. One
organism can link to several others.)
Using your desert organism cards create
your own food web.
The discussion questions in CScope are
excellent for all types of relationships in
the ecosystem. Be sure to discuss!
F April 8
DAY 15
After sharing out what they learned from the
Jigsaw Expert Cards,
Explain and Elaborate, p. 10 of 44
Journal:

Handout: Jigsaw Expert Cards (as needed)
Handout: Feeding Levels (as needed)
Handout: Feeding Levels KEY (as needed)
About the different trophic levels
Complete Feeding Levels. Divide the
string
Handout: Ecosystem Elaboration (1 per
group)
class into groups of 3 or 4. Give each group a
copy of the handout: Ecosystem Elaboration.
evaluate the food web from Lesson 01 on the
handout: Ecosystem Elaboration. Then have
the groups look at the simplified food web on
the handout: Ecosystem Elaboration Model.
Ask which organisms have been removed?
Handout: Ecosystem Elaboration
Example (1 per group)
Handout: Ecosystem Elaboration Model (1
per group)
What are the niches of the ecosystem?
Handout: Name Cards (1 per group)
What would happen if you removed the
rabbits?
Walk the students through the rabbit example.
5. Assign each group an organism to remove.
Have the students record what organism they
removed on the handout: Ecosystem
Elaboration. Then have them predict what
they think will happen to the other organisms.
Have them use the table and use the
appropriate letters (I, D, or U) to indicate their
prediction.
Have students build this Ecosystem
Elaboration Model out of string and name
cards. Have students wear an organism’s
name card. Connect the organism to all other
organisms that are connected in a feeding
relationship. After the web is built, talk through
the energy flow through the system. To
remove the rabbit, simply remove the rabbit
organism from the string system. Some strings
will fall. This will lead to discussion on how
removal of one organism affects many others.
Write a paragraph explaining why they made
their predictions. Predict what they think will
happen to the non-living components of the
ecosystem.
Share predictions with the class.