Lesson 1 – Energy Flow in
Ecosystem – all living and nonliving
things in an environment
* Biotic – living things (i.e. plant, animals)
* Abiotic – nonliving things (i.e. water, soil)
Lesson 1 Continued…
Population – includes all the members of a single
Food chain – the path that energy and nutrients
follow in an ecosystem
* The energy in a food chain starts with the sun. It
is the energy source for almost all organisms on
Lesson 1 Continued…
How are food chains alike?
Energy flows in one direction in food chains.
Producers are at the bottom of every food chain.
General pattern of a food chain!
Lesson 1 continued…
Consumers – any animal that eats plants or
other animals
* herbivores – animals that eat plants (squirrels, some birds,
some insects)
* carnivores – animals that eat other animals
(bobcats, hawks)
* omnivores – animals that eat both plants and
animals (raccoons, woodpeckers, mice, and some crabs)
* decomposers – break down dead or decaying plant and animal
material (fungi, bacteria, termites, and some worms)
Lesson 1 continued…
Predator – an animal that hunts other
animals for food
 Prey – organisms that are eaten by
other animals
Lesson 1 continued…
What are food webs made of?
Arrows pointing to an
organism show the living
things that organism eats
Arrows pointing away from
show the animals that eat
that organism
Lesson 1 continued….
How do energy pyramids compare?
When a producer is eaten, only 10% of the food energy it contains
gets turned into herbivore/omnivore tissue. The rest (90%) is lost!
It takes a H UGE number of organisms to support an ecosystem.
The bottom level (producers) is the largest level because it contains
the most organisms and also the most energy.
Food Chain Video
(15 min)
The Food Chain Mystery
Lesson 2: Relationships in Ecosystems
Why do organisms compete?
A limiting factor is any resource that restricts the growth of
A carrying capacity is the greatest number of individuals
within a population that an ecosystem can support.
If a jaguar population increases, food becomes harder for them to
Soon, the jaguar population decreases, which means their food
supply will rise back up.
The cycle starts all over again
Would you want to
survive by drinking
this water?
(algae is limiting factor)
Lesson 2 continued….
How do organisms avoid competition?
A habitat is the physical place where an organism lives and
hunts for food.
A niche is the special role an organism plays in a community
-example: 2 birds live in the same location and eat the same food. But
1 bird is active at night while the other is active during the day.
Therefore, the 2 birds can have different niches.
Swampland habitat
Ocean habitat
Desert habitat
Lesson 2 continued
How do organisms benefit from interaction?
Symbiosis a relationship between two or more kinds of
organisms that lasts over time
Types of Symbiotic relationships:
* Mutualism – benefits both organisms
* Commensalism –one organism benefits without
harming the other
(examples: Remora fish and rays/sharks; the growth of orchids on trees in the
rainforest; barnacles growing on the backs of whales.)
Remora Fish
riding on the belly
of a shark
Lesson 3: Adaptation and Survival
 What
is adaptation?
Adaptation – any characteristic that helps an organism survive in
its environment
Structural Adaptations are adjustments to internal or external
physical structures (examples: fur color, long limbs, strong jaws, the
ability to run fast, strong sense of smell, sharp teeth).
Behavioral adaptations are adjustments in an organism’s
(3min. 54sec. Video clip
about how animals make Structural
and Behavioral adaptations)
Lesson 3 continued….
What are some animal adaptations?
Protective coloration – a type of camouflage where the
color of the animal helps it blend in with its background.
 Mimicry – when an animal is protected against predators by
its resemblance to an unpleasant animal.
(Example: The king snake mimics the coloring of the poisonous
coral snake)

Chapter 3 Science Notes