Transcript Unit 9 Ecosystems Ch 8 Lessons 1 and 2

Unit 9 Ecosystems
Ch 8 Lessons 1 and 2
What Does an Organism Get From Its
Environment?
• An organism gets food, water, shelter and other
things it needs to live, grow, and reproduce from its
environment.
• A habitat provides the things an organism needs to
live, grow and reproduce.
What are the Two Parts of an
Organism’s Habitat?
• An organism interacts with both the living and
nonliving parts of its habitat.
• Biotic Factors
– Living or once living parts of a habitat.
– Examples- plants, animals, bacteria, animal waste
products and decomposing organisms.
• Abiotic Factors
– Nonliving parts of the parts of the habitat
– Examples- sunlight, soil, temperature, oxygen, water
How is an Ecosystem Organized?
• Organisms live together in populations and
communities that interact with abiotic factors.
• Organization of Ecosystems
– the smallest level of organization is a single organism,
which belongs to a population that includes other
members of its species. The population belongs to a
community of different species, The community and
abiotic factors together form an ecosystem.
•
What are Competition and Predation?
• Competetion- the struggle between organisms to
survive
– The role of an organism in its habitat is called its niche,
which includes:
•
•
•
•
•
the type of food the organism eats,
how it gets the food
what other organisms eat it
when and how the organism reproduces
the physical conditions it requires to survive.
• If two species occupy the same niche competition
will occur, causing one of the species to possibly die
off.
• Predation- when one organism kills another for
food or nutrients
– Adaptations are the behaviors and physical
characteristics that allow organisms to live successfully
in their environments.
– Predation can have a major effect on prey population
size
• If too many predators are in an area, a decrease in the size of
the prey population results.
• A decrease in the prey population results in less food for the
predator, causing the predator population to decline.
• Predator and prey populations rise and fall in
related cycles
Interactions Among Living Things
Predator-Prey Interactions
On Isle Royale, an island in Lake Superior, the populations of wolves
(the predator) and moose (the prey) rise and fall in cycles.
Symbiosis
• Any relationship in which two species live
closely together and that benefits at least one
of the species
What Are the Three Types of
Symbiosis?
• Mutualism
– Relationship in which both species benefit
• Commensalism
– Relationship in which one species is helped and the
other species is neither helped nor harmed
• Parasitism
– Relationship that involves one organism living with, on,
or inside another organism and harming it.
• The organism that is harmed is the host.
• Organism that lives on or in another and benefits is the
parasite. It is usually smaller and does not kill the host.
•
Mutualism
• Both organisms benefit from the relationship
Otters and
Kelp
The otters help the
kelp by eating the
sea urchins which
endanger it. The kelp
provides an anchor
for the otters while
they sleep.
Example 1:
Moray Eel with
Cleaner Fish
Moray Eel gets a
clean mouth
Cleaner Fish gets
a meal
Mutualism: both
benefit
Lichen
• Lichen is really two organisms: algae and fungus. The
fungus needs food but cannot make it. The algae
makes food but needs some way to keep moist. The
fungus forms a crust around the algae which holds in
moisture. Both organisms benefit.
Example 5:
Antelope with Oxbird
Antelope
gets rid
of
parasites
Oxbird
gets a
meal
Mutualism: both benefit
Swollen Thorn Acacia Tree and Ants
• The tree provides a
nursery for the ants in
the thorns and makes
special food for the
ant babies.
• In return the ants
sting and attack any
other plants or
insects that try to
invade the tree.
Example 4:
Clown fish with anemone
Clown fish
gets
protection
Anemone is
unaffected
Commensalism: one benefits,
one is unaffected
Example 3:
Cattle with cattle egrets
Cattle stir
up insects
as they eat
grass
Egrets
hang
around and
eat insects
Commensalism: one benefits, one is
unaffected
Barnacles and Whales
• Barnacles need a place
to anchor. They must
wait for food to come
their way. Some
barnacles hitch a ride
on unsuspecting
whales who deliver
them to a food source.
This does not effect
the whale in any way.
Oak Gall Wasps and Oak Trees
• The oak gall wasp
stings the oak tree.
• the tree then grows
a GALL which is a
nest for the wasp’s
babies.
• When the larva
hatch, they eat
their way out of the
gall.
• Does not help or
hurt the oak tree
Example 5:
Acacia plant with ant galls
Ants lay
eggs on
acacia tree
Acacia
covers the
infected
area with
brown fleshParasitism: one benefits,
(gall)
one is harmed
Parasitism
• One species benefits while the other is harmed
Mistletoe is an aerial
parasite that has no roots
of its own and lives off
the tree that it attaches
itself to. Without that tree
it would die. It slowly
chokes out the life of the
host tree.
Bedbugs
•
Bedbugs are small,
nocturnal parasites that
come out of hiding at
night to feed on
unsuspecting
humans. They feed
exclusively on
blood! Their bites often
result in an allergic
reaction.
Tapeworms
• The definitive host of the
cucumber tapeworm is a dog or a
cat (occasionally a human). Fleas
and lice are the intermediate
host. the dog or cat becomes
contaminated when the eggs are
passed in the feces, and the flea
or louse ingests the eggs. The
dog or cat (or human) is infected
when they ingest a flea or
louse. Hence the importance of
controlling fleas on your pet!
Example 6:
Taenia worm in human eye
Worm
infects
human
blood
stream
Human
may go
blind Parasitism: one benefits,
one is harmed