Learning Goal:
How is energy
transferred among
organisms in an
ecosystem??
All energy in an ecosystem
comes from…….
Nutrition is all about the transfer
of energy…..
2 ways
Making food
Eating food
Autotrophs
Heterotrophs
Producers
• Producers- (autotrophs) make their own food
(photosynthesis)
• Turn the suns energy into a form other organisms can obtain
• Ex. plants, some bacteria, algae
Consumers
• Consumers- (heterotrophs) get energy from other organisms
• Get energy through eating or absorption
• Ex. animals and fungi
Herbivores
• Eat only plants
• Ex. millipedes, rabbits, elephants, sloths, pandas,
bees, grasshoppers
Carnivores
• Eat meat
• Ex. cats, dogs, centipedes, sharks, seals, hawks
Omnivores
• Omni- all
• Can eat plants, animals, fungi
• Ex. Bears, raccoons, crows, primates
Decomposers / Detritivores
• They eat decaying/ decomposing matter (detritus)
• Ex. mushrooms and other fungi, crabs, maggots,
dung beetle, bacteria
Scavengers
• They eat dead organisms
• Examples: Catfish, vultures, flies, coyote,
polar bears, red ants
Food Chain
• Graphic display of who eats who in an ecosystem
• Arrows represent the direction of energy flow
Where does a food chain start?
• Food chains always
start with a
producer!
Primary consumers
• A primary
consumer eats the
producer.
• Primary consumers
are ALWAYS
herbivores!
Secondary consumers
• Secondary
consumers eat
the primary
consumer
• They are always
a carnivore!
Tertiary consumers
• Tertiary consumers
eat the secondary
consumers.
• Most tertiary
consumers are
omnivores!
Quaternary consumers
• Quaternary
consumers eat the
tertiary
consumers!
• Quaternary
consumers are not
in all food chains
Apex Predator
• The top predator of
a food chain is
called the apex
predator
• (No one can eat the
apex!)
Food Web
• Animals feed on more than one species
• A food web is a display of interconnected food chains
Trophic Level
• A group of animals that get their energy from the
same source (the sun, plants, rodents, snakes, bugs etc).
• Describes an organisms position in the food web
Quaternary consumer
Energy Pyramid
• Only 10% of the energy an organism stores is passed up to
the next trophic level. Therefore, 90% is “lost” or used for
heat and growth
Examine the food web shown in Figure 5-4. The disappearance of which of the
following pair of species would result in the total collapse of the food web?
A. algae and dragonflies
B. algae and elm trees
C. dragonflies and foxes
D. elm trees and bass
B: no producers = EVERYTHING
DIES
What would most likely happen to the organisms in this food web if the
robin began to disappear?
a. The hawk would be forced to start eating the dragonfly.
b. Most of the organisms in the ecosystem would starve and die.
c. The terrestrial organisms would starve, but the aquatic
organisms would survive.
d. There would be an overpopulation of caterpillars, which would
kill many elm trees.
What would most likely happen to the organisms in this ecosystem if
the algae began to disappear?
a. The bass population would increase.
b. All of the aquatic organisms would become overpopulated.
c. The minnow population would likewise begin to disappear.
d. The fox would begin to starve and be forced to emigrate to
another area.