Transcript Chapter 5 - TeacherWeb

Chapter 5
Life in Ecosystems
Lesson 1: What Are Habitats
and Niches?

Habitats
•

The natural
environment where an
organism lives.
Niche


An organism’s role in
the habitat.
Niche includes how an
organism grows,
reproduces, protects
itself and behaves.
Adaptations

Animals have different
adaptations that help
them to survive in their
habitat



Polar Bears have thick fur
and heavy padding to stay
warm
Sea Turtles have flippers
and rounded shells
Desert Turtles have sharp
claws and flat shells to help
them survive
Some Adaptations can
be physical, while
others are behavioral
Natural Selection

Natural Selection is
the process in which
surviving individuals
pass on the
characteristics best
suited for the survival
in their environment.
Symbiosis

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Symbiosis is a close, long-lasting relationship between
two different organisms
There are three kinds of symbiosis:

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1. Parasitism
2. Commensalism
3. Mutualism
Parasitism

Parasitismwhere the
parasite benefits
and the “host” is
harmed

Example: A
hookworm takes
blood and
nutrients from
its host, and
the host is
harmed
Commensalism

Commensalismwhen one organism
benefits and the
other goes
unaffected

Example: An elf owl
makes its home in a
cactus. The owl
benefits, the cactus
is not affected.
Mutualism

Mutualism- when both organisms benefit
from the relationship.

Example: A cleaner shrimp eats parasites attached
to the fish, so both benefit. Shrimp eats, and the
fish stays clean. http://video.nationalgeographic.com/video/k
ids/animals-pets-kids/fish-kids/fishsymbiosis-kids/
Lesson 2: What Factors
Affect Ecosystems?
Changes in Populations and
Ecosystems
Main Idea
The size of any
population can vary
over time.
 It responds to
changes in climate
and resources.

A Balanced Ecosystem

A population is all the organisms of a given
species that live together in the same area.
Limits on Populations
Predators are animals
that hunt/eat other
animals
 Prey are animals that
are hunted/eaten.
 In a healthy
ecosystem,
populations of
predators/preys are
balanced.

Changing the Balance
Ecosystems may
never recover once
they are changed
 Alien Species are not
native to an
ecosystem



Can change an
ecosystem significantly
Usually enter into the
United States
unknowingly

Zebra mussels
 Came
over on ships from Russia.
 dumped into great lakes.
 clog water pipes,
 smother native species (ex: clams)


http://www.nationalatlas.gov/articles/biology/a_zm.html
Long Horned Beetle
 Traveled
from Asia on wooden ships,
 Burrow under the bark of trees, slowly killing
them
Nonliving Organisms
Can also change the
ecosystem
 Including Natural
events such as
volcanic eruptions,
forest fires and
droughts.

Adapting to Change

Living things respond
to change in their
environment by


adapting, relocating,
or perishing (dying).
Change can cause
extinction:


all the members of a
species die out.
Fossils show different
species lived at
different times.
Evidence in Rocks
Scientists estimate
the age of a fossil
through radioactive
dating.
 Mass Extinction:
believed happened to
the dinosaurs, (all
species die at once.)

Climate Change

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Earth’s climate changes
over time.
During ice ages, North
America/Europe covered
by glaciers.
Woolly Mammoth and
Saber-toothed Cat were
in N. America.
Scientists believe human
activity/climate change
caused extinction.
Lesson 3: How Can Humans Change
Ecosystems?

Human Activities
 Impact
the ecosystems in both negative/
positive ways.
 Rainforests are a valuable resource. They
produce oxygen, and are home to many
different species.
 Many plants/animals become extinct when
habitats are destroyed, effects many
ecosystems.
Effects on different species
Habitat destruction: main reason why
rates of extinction are rising.
 Wetlands: help to absorb harmful
chemicals from groundwater.
 A species that is close to becoming extinct
is Endangered
 A species close to becoming endangered is
threatened.

Pollution

The three types of
pollution are :
______, ________,
and ________

Examples include, Oil
spills, trash and
garbage, and burning
fossil fuels.
Growth and Human Population

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Increased human
population causes greater
demands on limited
resources
People need shelter,
food, clean water, clean
air, and resources.
Increased amount of
humans has destroyed
some ecosystems and put
a strain on others
Government Involvement

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The government is
creating and enforcing
new laws to protect the
environment
Industry is being given
clean- air guidelines to
prevent further damage
to ecosystems
Individuals are also doing
what they can to reduce
pollution, and restore
damaged ecosystems.