Transcript Food Webs - JhaveriChemBioWiki

Food Webs

Catalyst:
 Examine
the food
web to the right.
 Tell me at least
FIVE conclusions
you can draw from
it.
Write in complete sentences!
Don’t talk during the Catalyst!
Agenda





Evolution Mastery
Introduction to Environmental Science
Food web roles
Whiteboard fun!
Food web interactions
 Predation,


competition, extinction
MOOOORE Whiteboard fun!!!
Closing/Exit Question
SI 13: Identify scientific evidence that has
caused modifications in previous theories
3
59.3
LS 17: Explain how factors affect gene
frequency in a population over time
3
75.2
LS 16: Explain how DNA/fossil
evidence supports evolution
3
82.3
LS 15: Compare the embryological
development of animals
4
83.3
LS 14: Analyze evidence of
evolution
3
62.7
ES 9: Cite and explain examples of
adaptations over time
3
63.6
Unit 6 Mastery Overall
3
71.1
Introduction




First, we studied how individual cells work.
Second, we learned how cells fit together into
organisms and reproduce.
Then, we discovered how organisms change (evolve)
over long periods time.
Now, we will study how groups of these organisms
interact and change the environment around us.
We will also look at how our treatment of the
environment threatens the survival of the human
species.
This Is Environmental Science

Objective
By the end of today, all SWBAT…
 Analyze food webs by predicting
the impact of the loss or gain of
an organism
Catalyst Review
Examine the food
web to the right.
 Tell me at least
FIVE conclusions
you can draw from
it.

How Do Organisms Interact?


They eat each other!
Key Point #1: A food web shows all the
feeding relationships in an ecosystem.
 Ecosystem:
all of the living and non-living
things in an area.
First, some vocabulary…


Producer: another word for autotroph.
Makes its own food through
photosynthesis.
Consumer: another word for
heterotroph. Eats other things for
energy.



Primary consumer: eats producers.
Secondary consumer: eats primary
consumers.
Tertiary consumer: eats secondary
consumers.
Some things to notice…



Arrows show the flow of
energy. So, they point FROM
something getting eaten TO
whatever is eating it.
A food chain is a path on a
food web. From producer to
the final consumer.
The most basic level of the
food web is the producer.
Where does it get its energy
from?
Guided Practice (GP) 1
The arrow pointing
from seed-eating
birds to foxes
shows that...
A.
Foxes eat birds
B.
Birds eat foxes
C.
Foxes and birds
share food
D.
Foxes and birds
compete for the
same food
Guided Practice (GP) 1
Although it is not
shown in this
picture, where
does all of this
food web’s
energy begin?
A.
B.
C.
D.
The Moon
The Earth
The Sun
Fertilizer
Guided Practice (GP) 1
What is the producer
in this food web?
A.
B.
C.
D.
Hawks and owls
Squirrels
Plants
Spiders
Guided Practice (GP) 1
Which of the
following is a
secondary
consumer in this
food web?
A.
B.
C.
D.
Toads
Plants
Mice
Spiders
Guided Practice (GP) 1
Which of the
following is a
primary consumer
in this food web?
A.
B.
C.
D.
Snakes
Mice
Predaceous
insects
Foxes
Guided Practice (GP) 1
I need one volunteer
to come up to the
board and circle
a food chain.
What If…?

Key Point #2: We can use a food web to predict
what will happen when we introduce/take away
a species
 Three
important interactions for you to learn.
Food Web Interactions


What do you think will
happen to the rabbits, if all
the vegetation is destroyed?
If a population loses ALL of
its food sources, it will
become extinct.
Food Web Interactions


What do you think will
happen to the cougar, if all of
the deer die?
If a population loses SOME
of its food sources, it will
decrease in size.
Food Web Interactions


What do you think will
happen to the mice, if all of
the foxes are eaten by the
cougars?
If a population loses its
predators, it will increase in
size.
Guided Practice (GP) 2
What will happen to
the mouse
population, if a
disease kills all
the plants?
A.
B.
C.
D.
All will go extinct
Increase in size
Decrease in size
Reproduce more
Guided Practice (GP) 2
Imagine that a bobcat
enters the
ecosystem. Bobcats
eat insectivorous
birds. What will
happen to the fox
population?
A.
B.
C.
D.
All will go extinct
Increase in size
Decrease in size
Move elsewhere
Guided Practice (GP) 2
Imagine that a disease
kills all of the snakes
in the ecosystem.
What will happen to
predaceous insect
population?
A.
B.
C.
D.
All will go extinct
Increase in size
Decrease in size
Stop eating
herbivorous insects
Guided Practice (GP) 2
What will happen to
the squirrel
population, if a
cow wanders by
and eats all the
plants?
A.
B.
C.
D.
All will go extinct
Increase in size
Decrease in size
Start eating toads
Guided Practice (GP) 2
What will happen to
the rabbit
population, if a
drought kills all
the plants?
A.
B.
C.
D.
All will go extinct
Increase in size
Decrease in size
Eat foxes
Guided Practice (GP) 2
Imagine that a hunter
kills all of the hawks
and owls in the
ecosystem. What
will happen to the
seed-eating bird
population?
A.
B.
C.
D.
All will go extinct
Increase in size
Decrease in size
Begin eating spiders
Guided Practice (GP) 2
Pretend that a falcon
enters the
ecosystem. Falcons
eat toads. What will
happen to the snake
population?
A.
B.
C.
D.
All will go extinct
Increase in size
Decrease in size
Stop eating toads
Guided Practice (GP) 2
Imagine that a
population of bears
wanders into the
ecosystem. Bears
eat foxes. What will
happen to the
squirrel population?
A.
B.
C.
D.
All will go extinct
Increase in size
Decrease in size
Move elsewhere
Independent Practice

Make your own food web. (You don’t actually have
to draw each animal, if you don’t want to. You can
just write their names.)
 Your
food web must have at least FOUR producers,
TWO primary consumers, ONE secondary consumer,
and ONE tertiary consumer.

Describe two situations in which an organism
enters/leaves your food web. Explain what will
happen to the other organisms in your food web as
a result.
Key Point Wrap-Up


KP#1: A food web shows all the feeding
relationships in an ecosystem.
KP#2: We can use a food web to predict what
will happen when we introduce/take away a
species
 If
a population loses ALL of its food sources, it will
become extinct.
 If a population loses SOME of its food sources, it will
decrease in size.
 If a population loses its predators, it will increase in
size.
Exit Questions
A
Use the food web at right to
answer the questions below.



What animal eats the elk?
What would happen to the
rabbit population, if all the
grass were to be burned
down in a fire?
Imagine that a population of
foxes wanders into this food
web, and eats all the mice.
What will happen to the
cricket population?
B