Chapter 1:
Interactions of Life
Sections 1 & 3
Life Science

Ecology is the study of interactions
among living things and their
environments.

Ecologists are scientists who study
those interactions.
What is a Biosphere?

Biosphere- part of the Earth that
supports life.

Biosphere is made up of different
Environments that are home to many
different kinds of organisms.
What is an
Ecosystem???

Ecosystems- consist of all the living
organisms and the non-living things in
their environment.
Living Things
Biotic Factors – a living thing
in an ecosystem

Abiotic Factor

Abiotic Factors – any physical or
chemical part of an ecosystem that
living things NEED to survive.
– Sunlight
– Water
– Air
– Soil, Sand, Rocks, etc.
– Proper Temperature
iPads!!!

Create your own Ecosystem using the
LINO APP!
Populations

Populations- made up of all the
organisms in an ecosystem that
belong to the same species.

Example- Human Population!
Community

Community- all the populations in an
ecosystem.

Example– Arctic Community: fish, seals, polar
bears.

Habitat- the place in which organisms
live
– Provides: food & shelter, proper
temperature, and Living space the
organism NEEDS to survive.
- Example – Pond
Niche – an organism’s role or job
in the habitat.

Section 3: Interactions
with Communities

What is a Community?
Where does all the Energy come
from?
 SUN!


What is affected? How?

Energy from the sun is stored in
chemical bonds that holds together
Atoms.

When these chemical bonds are
broken, what must be released?

All organisms need energy in one way
or another….
PRODUCERS
 Producers:
organisms that
use a source of energy to
make food
 Example: Plants use sun for
Photosynthesis
What if organisms can’t
receive sunlight?
– is when
bacteria produces food using
heated chemicals released
from underwater vents.
 Chemosynthesis
CONSUMERS
Consumers: Organisms that cannot
make their own food
 AKA - Heterotrophs

1.
Herbivores- “vegetarians” plant
eaters

2.
Carnivores- animal eaters

3.
Ex- Lions, Coyotes
Omnivores- eats plants & animals

4.
Ex- Rabbits, Deer, Cows
Ex- Humans, Bears
Decomposers- consume waste &
dead organisms

Ex- Earthworms, Mushrooms, Mold, Fungi
- help recycle once-living matter
– an organism that
feeds off of once-living organisms
 Scavenger
– Ex – turkey vulture

What are some things that organisms
depend on other organisms for?
FOOD CHAIN

Food Chain- a model to show the
feeding relationships between a single
producer and a chain of consumers
FOOD WEB

Food Web – model of the feeding
relationships between many
overlapping food chains
ENERGY PYRAMID

-shows the amount of Energy
available at each feeding level.
 STOP HERE 
What are some
“cycles” in nature?
Section 2

Cycles – Picture Notes (see Binder)
BIOMES – Section 4

See Biome Project in Binder
Chapter 2:
Interactions Within
Ecosystems
Life Science
Habitats & Niches

Habitat- the place in which organisms
live
– Provides: food & water, shelter, proper
temperature, and Living space the
organism NEEDS to survive.
- Example – Pond
Niche – an organism’s role or job
in the habitat.

Niches

What is a Niche?

Niches- how an organism survives,
how it obtains food and shelter, how it
finds a mate and cares for its young,
how it avoids danger.
– Special adaptations that improve survival
are often part of an organism’s niche.
Patterns Exist in
Populations

Patterns in SPACE - how animals or
plants place themselves, depends on
how they meet their needs to survive.
– Space is needed for food or water.

Examples – School of fish, herd of
elephants
Patterns in
Populations

Patterns in TIME
– Population sizes change depending on
climate.
– Examples – Cicadas emerge every 17
years, bears hibernate, birds migrate, jelly
fish in August!
Population sizes can also
depend on predators.

SECTION 2.2
Symbiotic
Relationships
 Symbiotic
Relationship –
means a close relationship
between two species
MUTUALISM
1.
Mutualism- where both species
benefit
Example: Bee and Flower
Explain…
COMMENSALISM
2.
Commensalism- where one
organism benefits and the other is
not affected
Example: Clown Fish and Anemones
Explain…
PARASITISM
3.
Parasitism- where one organism
benefits, and the other is harmed
Example- Dogs and Ticks
PREDATOR/PREY
 Predator-
consumers that capture
and eat other consumers
– Predators can limit the size of
populations
– Predators can also increase &
decrease the number of different
organisms in an ecosystem.
PREDATOR/PREY

Prey- organism that is captured by a
consumer (or predator)
Competition

Competition- two or more organisms
that seek the same resource at the
same time.
Effects of Competition

Competition for food, living space, or
other resources can LIMIT the
population.
– Prevents Pop. Growth

Competition is most intense among
individuals of the same species.
Measuring Pop.
Methods
1.
2.
3.
Count the # of species
Trap-Mark-Release
Sample Count (used to estimate the
sizes of larger populations)
Population Size

Pop. Size- indicates whether
population is healthy and growing.

Population Density- the size of a
population that occupies a specific
area

Limiting Factor- anything that restricts
the # of individuals in a population.
– Can be living or nonliving
– Can affect other populations

Carrying Capacity- the largest # of
individuals of one species that an
ecosystem can support.

What if the Carrying Capacity
exceeds?

Not enough resources, death occurs,
species are forced to move.
What Affects Pop. Size?

List some things that can affect
Population Sizes…
Exponential Growth

Exponential Growth- the LARGER a
population becomes, the FASTER it
grows.
Changing in Pop.

Populations can change in size when
new members enter or exit the pop.
BIRTH RATE- # of births in a given
time
 DEATH RATE- # of deaths in a given
time
