Transcript B(4-3) How do organisms interact? Vocabulary competion symbiosis parasite host Copyright © Houghton Mifflin Harcourt Publishing Company Limiting factors – competition for resources • Organism compete for space, light, food, water, and.

B(4-3) How do organisms
interact?
Vocabulary
competion
symbiosis
parasite
host
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Limiting factors –
competition for resources
• Organism compete for
space, light, food, water,
and nutrients.
• Competition is the
struggle among organisms
for limited resources in an
area.
• Every ecosystem has
limited resources, so all
species must compete to
stay alive.
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Limiting factors –
competition for resources
There are several types of
competition an ecosystem.
1. In one type one species
might prevent another
from using an important
resource. ex. Some plants
release certain chemicals
that prevent other plants
from growing.
2. When organisms use the
same resources they
usually have different
niches. Ex. Warbler birds.
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Limiting factors –
competition for resources
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The predator-prey
relationship also
affects competitions
for resources in an
ecosystem.
A predator is an
animal that feed on
other living animals.
Prey is an animal
that predators eat.
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Limiting factors –
competition for resources
Factors affect population:
1. Plants supply affects the Hare population.
2. The prey supply affect the predator population.
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Organisms interact to meet their
needs
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Not all organisms in an
ecosystem compete.
Some organisms live
together in a relationship
called symbiosis.
Symbiosis is a close
relationship between
organisms of different
species in which one or
both of the organisms
benefit.
There are three types of
symbiosis.
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Parasitism
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In parasitism, one species
benefits while the other is
harmed.
Parasite is an organism
that lives in or on another
organism.
The organism that a
parasite live in or on is
called the host.
Parasites are usually
smaller than their hosts.
Although they can weaken
their hosts, parasites
usually don’t kill them.
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Parasitism
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Some parasites
live at the
outside of their
hosts. Ex. Ticks
and flees.
Other parasites
such as the dog
heartworm, live
inside hosts.
Plants can be
hosts for
parasites too.
Ex. Red spider
mites and tick
like animals
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Mutualism
•
In mutualism both organisms benefit.
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Commensalism
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In commensalism one organism benefits and the other
is neither helped nor harmed.
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