Transcript Energy Flow through Food Webs

Welcome!
Please read the board carefully.
Test review – Course
Foundations
Objective #4 Ecosystem services
• Things our natural areas do for us.
– Air purification (plants take in CO2, produce
O2)
– Flood control (prairies absorb water to protect
our homes)
– ***Ecosystem services happen when an
ecosystem is healthy and not destroyed!
Return to the front:
• Test questions
• Course Foundation Objective sheet and
answers
Ecology – the study of relationships
between organisms and their
environment
Biotic vs. Abiotic
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Mockingbird
Oak tree
Bacteria
Bison
Human
Ladybug
Leaves on the ground
Deer antler
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Air temperature
Water pH
Waves
Fire
Wind
Sunlight
Humidity
Energy Flow through Food
Webs
Energy
• All living things need energy to survive.
• The sun is the ultimate source of energy
for the earth.
• Trophic levels – an organism’s position
in the food chain
Producers
• Also called autotrophs
– Auto (self), troph (feeder)
• Can take the energy from
sunlight and make food
– Plants, Bacteria, Protists 
Photosynthesis
– Some ancient forms of bacteria
can also use chemicals to make
food (deep-sea vents) 
Chemosynthesis
Consumers
• Need to eat other
organisms in order to
survive.
• Cannot make their own
food through
photosynthesis or
chemosynthesis.
4 types of Consumers
• 1. Carnivore
– Eat only other consumers
• 2. Herbivore
– Eat only plants
• 3. Omnivore
– Eat both plants and animals
• 4. Decomposers
– Eat dead organisms
Think, Pair, Share
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What category would the following
organisms be classified under?
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4.
5.
Producer or Consumer
Carnivore, Herbivore, Omnivore, Detritovore
Human
Horse
Mouse
Shark
Fungus
Food Chains
• Show the feeding relationships between
different organisms
Synonyms
• Producer, Primary
Consumer, Secondary
Consumer, Tertiary
Consumer
– Are labeled in the order
in which the energy
travels to them.
– These are called trophic
(trow-fic) levels
• What trophic level is
the mouse on?
• What two organisms
are producers?
Food Webs
• A series of interconnected food chains
What would happen to the
population of spiders if the insect
eating birds were removed from
the food web?
Can you predict any other
outcomes if the insect eating
birds are removed?
Energy Flow
• Arrows are used in a food chain to show
THE DIRECTION IN WHICH ENERGY
IS MOVING!
Get ready to show me what you
know!
Secret of the arrows
• If you know the secret, you can identify the
trophic levels even if you don’t know the
organisms.
Food Webs & Energy Flow:
Secret of the arrows???
1. In this food chain, the
spiders are —
A producers
B primary consumers
C competitors
D secondary consumers
2. As energy flows from one trophic level to
the next, how much energy is actually
available for organisms at the next level?
A. 80%
B. 5%
C. 10%
D. 100%
Trophic Levels
• Energy is always lost as it moves from
one trophic level to the next.
– Why would energy be lost as it moves from
producerconsumer?
• Energy is lost through heat during the chemical
reactions that break food down
10% Rule
Only 10% of energy is
available for organisms of the
next trophic level.
This is also why there
are more organisms
on the lower levels of
the energy pyramid
and lower numbers of
top consumers. There
is more energy
available at the
bottom of the
pyramid, less at the
top.
Exit Ticket
• Label the top of your paper with the
following:
– Your name and period
– Exit Ticket
Warm-Up
• What did you eat for dinner last night?
– Draw a food chain or web that shows you at
the top of the pyramid, and the sequence of
organisms that the food you ate consumed.