Transcript Ch 2 Power point

Chapter 2: Interactions in
Ecosystems pg. 32
2.1 Types of Interactions p. 34
Symbiosis:
- is a biological relationship in which two
species live closely together over time.
- Helps each species survive by providing
food, shelter and protection.
- 3 types of relationships exist:
a. Parasitism
b. Mutualism
c. Commensalism
a. Parasitism
• One partner is called the “host” and the
other a “parasite”.
• Host is usually bigger and is harmed
• Host does not usually die but their lifespan
may be shortened.
• Parasite obtains food and shelter from host
and benefits.
• Parasites can be internal or external.
Internal Parasites
• Live inside bodies of
hosts
• May stay a long time.
• Ex. Tapeworms,
roundworms
External Parasites
• Live on the surface of
hosts
• May stay a short time
to feed and reproduce
b. Mutualism
• Both partners benefit
• Ex. Lichens, bees and flowers, termites
lichens
• Grow on solid surfaces
like rocks and trees
• Consist of an algae and a
fungus living together
Lichens
• Algae makes sugar
just like plants which
is food for both
• Fungus anchors both
organisms to a surface
and absorbs water
needed by both
Insects and flowers
• Insects carry pollen
away and help
reproduction
• Flower provides food
(nectar) to the insects
mutualism
•
•
•
•
•
Bacteria living inside humans
Birds living on zebras and rhinos
Algae living on backs of spider crabs
Microorganisms living in the gut of termites
Sea anemones and hermit crabs
c. Commensalism
• One partner benefits
and the other does not
gain or lose anything.
Ex. Barnacles on the back of a
whale
Ex. Birds follow army ants
Birds riding on water buffalo
Food and Populations pg. 37
• Symbiosis helps an organism survive
because it provides: ______________
• Predators
– are organisms that hunt and kill their food
– Are carnivores or meat eaters
– Ex. ______________________________
Cont’d…
• Prey
- are organisms that are hunted and killed
for prey.
- ex._____________________________
Predator-Prey Relationships
• often show changes in the size of each
population that repeats in a cycle.
• size of predator population is affected by
the number of prey that are available
• size of predator population is affected by
the number of prey hunting them
Lynx- Hare Populations
2.2 Roles of Organisms in Ecosystems (Niche)
Producer
Consumer
• Organisms that get
• Organisms that make
their food by eating
their own food
other organisms
through a process
a. Herbivores
called
b. Carnivores
photosynthesis.
c. Omnivores
• Ex. Plants, algae,
d. Scavengers
some bacteria
e. Decomposers
Photosynthesis –
Producers/Autotrophs
Bacteria – algae that live ina
pond
Plants – over 300 000 species on
Earth
Diatoms – plankton live in the
ocean
Types of Consumers
a. Herbivores
- eat only plants
ex.
b. carnivores
• Hunt and eat other animals
• Ex.
c. omnivores
• Eat both plants and animals
d. scavengers
• Eat remains of dead plants and animals
• Ex. Seagulls, crows, blackbears, raven,
hawk, eagle
e. decomposers
• Do not ingest food
• Release digestive juices to the environment
which break down remains of dead
organisms and waste
• Absorb the digested from back in
• Ex. Bacteria, fungus, insects
Decomposers and Food pg. 43
• Food can be protected from decomposers
by:
1. Keeping microorganisms out of it. (bacteria,
fungus, )
a.
b.
c.
d.
e.
f.
Vacuum packed products
Caning
Sealed plastic bags and containers
Freezing
Freeze Drying
Salting and pickling
Micro-organisms
• Need a source of food
• Need water
• Have a range of tolerance for temperature
and ph
a. Vacuum Packed Products
b. Canning
c. Containers and bags
d. Freezing food
e. Freeze Drying
f. Salting food
Pickling food
2. Killing or slowing growth of
microorganisms already on it.
a. Washing hands, utensils and countertops
before handling food
b. Washing food
c. Cooking food well
d. Radiation
Microbes Make Food –
Fermentation (to bubble)
• Is a process carried out by microorganisms
where they break down sugar and produce
different kinds of waste products:
1. Lactic acid – stops growth of harmful
bacteria, used to make dill pickles, sauerkraut,
pickled cabbage, some sausages, cheese
2. Alcohol – used to make beer, wine
Cont’d
3. Carbon dioxide – used to make bread rise
Fermentation in beer
Fermentation in cheese
Fermentation in bread.
Food Webs
Energy Pyramid
2.4: Cycles of Matter in Ecosystems
Nutrients:
- Are substances contained in food that are
needed in small amounts by all living
organisms
- Are taken in from the environment by
producers
- Are transferred to consumers through a food
chain/web
- Are reused when living organisms die and
are broken down by decomposers.
Cont’d…
Ex. Minerals come from the soil
Ex. Water
Ex. Carbon comes from
carbohydrates and carbon dioxide,
Ex. nitrogen comes from protein
Nutrient Cycles
• Are processes that move nutrients back and
forth between the biotic and abiotic parts of
the ecosystem.
• Ex. Carbon – Oxygen Cycle
• Ex. Nitrogen Cycle
• Ex. Phosphorous Cycle