1. What is Ecology?
2. What would you call a person who
Who Eats Whom???
1. Arrange the cards on your desk in a chain to show
who eats whom.
2. In nature, would you expect to see more cougars,
more deer, or more oak trees?
3. Arrange the organisms in order of most to fewest
4. What might happen to the other organisms if the
oak trees were removed? The cougars?
5. Are there any organisms in this group that eat more
than 1 kind of food?
• The study of the
organisms and their
Biotic Factors: living parts
of an ecosystem
Abiotic Factors: non-
5 Levels of Organization:
1. What is the difference between
abiotic and biotic? Give an example
2. What is the difference between an
organism and a population?
Graph the following to show how populations grow:
1800, 1 billion people
1930, 2 billion people
1960, 3 billion people
1975, 4 billion people
1987, 5 billion people
1999, 6 billion people
1. What does the curve you have drawn indicate about
human population growth?
2. Do you think the human population can continue to grow
3. Why or why not?
• Every organism has a niche or
a role in an ecosystem based
on how it gets energy.
Producers: organisms that get
energy from sunlight and make food.
Ex: plants, plankton,
Consumers: organisms that eat
producers or other consumers.
Primary: eat producers
Secondary: eat primary consumers
Tertiary++: eat secondary consumers, etc.
Consumers can be:
Herbivores: eat only plants
Carnivore: eat only other consumers
Omnivore: eat either producers or consumers
Scavenger: eat dead animals
Cockroaches have survived on
Earth for over 300 million years as
the most successful scavenger!
Dead skin, fingernails, shoe polish,
and even paint are unlikely food
sources for these animals
Decomposers: organisms that get
energy by breaking down the
remains of dead organisms.
• shows how
organism to the
1. What is the producer in the ecosystem above?
2. What is a carnivore in the ecosystem above?
3. What is an omnivore in the ecosystem above?
… and Food Webs
•Complex web of interlocking food
all of the
1. What is the difference between a
population and a community?
2. What is the space on Earth where all
living things exist called?
energy is lost
as it is
• Grass (at the base of the energy pyramid)
has 12,000 units of energy available from
• 10% is lost at each step of the pyramid.
• Calculate the food energy stored by each
of the following in the food chain/energy
pyramid: grass, rabbits, coyotes
• Create an energy pyramid for a river
ecosystem with 4 levels:
– Aquatic plants
– Insect larvae
– Bluegill fish
– Largemouth bass
• Plants have 10,000 units of energy available
• Each level uses 90% of what is available
Interactions in an ecosystem…
• What factors interact?
• Populations cannot grow indefinitely
• Carrying capacity
– Limiting factors