Transcript Organisms & Their Environment

Nutrient & Energy
Flow
2.2
I. Producers vs. Consumers
A. Producers / AutotrophsOrganisms that can make their own
food/sugars.
1. Plants are autotrophs & some
bacteria
2. Use light energy, carbon dioxide
and water to create sugar and give
off oxygen
Sun + CO2 + H2O => C6H12O6 + O2
(This is the equation for photosynthesis)
I. Producers vs. Consumers
B. Types of Heterotrophs
(obtain their food)
1. Herbivore- Eats only
plants
=
2. Carnivore- Eats
only other
animals
3. Scavenger- Eats only
other animals that have
already died
4. Omnivore- Eats both
I. Producers vs. Consumers
5. Decomposer- Break down
complex compounds of dead
organisms and release nutrients
a. Usually bacteria or fungi
=
b. Important for completing
the cycle of nutrients
c. Used in landfills to speed
the rate that wastes get
broken down
II. Trophic Levels
A. “Troph” = Food/Energy
1. Explain auto”troph” and
hetero”troph”
B. Trophic Levels represent
the different steps in a
food chain or web.
1. Shows how energy is
transferred
II. Trophic Levels
3rd – Order
Heterotroph
2nd – Order
Heterotroph
1st - Order Heterotroph
Autotroph
III. Food Chain vs. Food Web
A. Energy and other nutrients
that are eaten flow from one
organism to the next.
B. Food Chain- Simple
model
=
that shows how matter and
energy move through an
ecosystem (one organism to
the next)
III. Food Chain vs. Food Web
1. Autotroph -> Heterotroph -> Decomposer
2. Ex: Berries (autotroph) are eaten
=
by a mouse (heterotroph)
who dies
and decays (decomposer)
3. Some energy is lost as heat at
each level
III. Food Chain vs. Food Web
C. Food Web- Model of ALL
possible feeding
relationships in a community.
1. More complex= than food
chains (more realistic, too!)
a. See pg. 43 for picture
2. Most organisms do not
rely on just one food source
III. Food Chain vs. Food Web
Go outside…
1. Write down one example of
a simple food chain that you
see.=
2. Write down one example of
a food web that you see.
Energy Pipeline
Demonstration
=
(Takes entire class
period)
(Sept. 18, 2008: Lead by
guest speaker from Game &
Parks)
IV. Ecological Pyramids
A. Ecological pyramids show
amounts at each trophic
level.
1. See pg. 44for Energy,
=
Numbers and Biomass
Pyramids.
2. Notice: the number at
each level sometimes goes
up, sometimes it goes down.
IV. Ecological Pyramids
B. Test Practice: Study this
ecological pyramid. There will
be questions on the next slides.
Large
Bird
Snake
Small Bird
Grasshopper
IV. Ecological Pyramids
1. Which animal will eat the
largest numbers of its prey?
The small bird will eat many
grasshoppers
Hint: What has
more calories,
steak or salad?
Large Bird
Snake
Small Bird
Grasshopper
IV. Ecological Pyramids
2. Which level will have the
highest concentration of
pesticide particles in the
digestive tract? Explain.
The large bird is highest. The
concentration will increase at
each level because each animal
below eats many of the
pesticide-infested animals.
V. Cycles
Not true of
energy…It is
A. Law of Conservation of created
by the
sun and is
Mass: Matter is neither destroyed
all the
time!
created or destroyed.
1. Therefore it must be
RECYCLED or we would run
out!
2. Matter includes water,
carbon, nitrogen, phosphorus,
etc.
V. Cycles
B. Explain the Water Cycle Below
V. Cycles
Feel like doing some theatre? As
a class, read the “Water Cycle
Play” script for another look at
how water is recycled.
(Time Permitting)
V. Cycles
C.Explain the Carbon Cycle below
V. Cycles
1. Remember that all living
things have carbon. We call
this “organic.”
2. The “global warming” is
caused by raising levels of
carbon (CO2) let off by
industry?
a. For an “other assignment”
research the question, “Is global
warming really caused by humans?”
V. Cycles
D. Nitrogen Fixation- Converting
nitrogen gas in the atmosphere to
ammonium (nitrogen) compounds
in the soil for plant growth
1. Taken up by roots
2. This is done by bacteria in
the soil or on the roots
a) Ex: soy beans, alfalfa
3. See pg. 48 to study diagram
V. Cycles
E. Denitrification- Converting dead
organisms into nitrogen gas in
the air
1. Done by decomposers
VI. Limiting Factors
A. Limiting Factor- Any thing that
limits the number of individuals
in a population
1. Can be living (biotic)
a. Amount of grass available
for
cattle to graze
2. Can be non-living (abiotic)
a. Amount of rain affects
how much grass can grow
VI. Limiting Factors
3. Common Limiting Factors
a. Food & Water
b. Space
c. Shelter
d. Moisture
e. Temperature
VI. Limiting Factors
Play “Oh Deer” to simulate
and graph how limiting
factors affect populations
(Time permitting—Takes at
least 30 minutes)
VI. Limiting Factors
B. Carrying Capacity- The
largest number of individuals
of one species that the
ecosystem can support.
1. Carrying capacity exists
because of limiting factors!
VI. Limiting Factors
2. What can we do to
INCREASE carrying
capacity?
a. Plant trees
b. Waste less
c. Use biotechnology to
increase food supply
d. Health Care/Medicine
Review
What’s the difference
between an autotroph and
heterotroph?
List the 5 kinds of
heterotrophs.
Give an example of a
st
nd
rd
producer, 1 , 2 , and 3
order heterotroph.
Review
Give another name for the
top consumer in a food
chain.
What is the difference
between a food chain and
food web?
Why are cycles important on
earth?
Review
Is energy recycled?
Define nitrogen fixation.
List three limiting factors in
an ecosystem.
If there are a lot of limiting
factors will the carrying
capacity be high or low?