Transcript Relationships Among Organisms

Communities
Communities
Populations live in groups of other
populations which form communities.
Community- is a group of species that live
in the same habitat and interact with each
other.
Abiotic and Biotic Factors
Abiotic- Any non living factor within an
ecosystem.
Biotic-Any living factor within an
ecosystem.
Symbiosis
Symbiosis- Any close relationship between
species
Competition
Competition- occurs between two
organisms when they compete for the same
resource.
In most cases of competition one species
benefits and the other is unaffected or
harmed.
Competition
Competitive exclusion- When two
organisms compete for resources the species
which uses the resources more efficiently
will eventually eliminate the other.
Mutualism
Mutualism- A symbiotic relationship in
which both species benefit.
Commensalism
Commensalisms- A symbiotic relationship
in which one organism benefits and the
other is not affected.
Parasitism
Parasitism- A symbiotic relationship in
which one organism benefits and the other
is harmed.
Parasite
 Host
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The horsehair worm: It starts as an egg in a
puddle. When the puddle dries out a grasshopper
usually comes along and eats it. It then burrows
into the insects gut and grows. When it is an adult
it produces chemicals that make the insect seek
out water and jump into it. The worm will exit the
grasshopper and finish out its life in the puddle.
The grasshopper may survive the ordeal if it
doesn’t drown.
Parasitism
Do parasites kill their host? Why or why
not.
Endoparasite- internal parasites
Ectoparasites- external parasites
Predator
Predator- Consumers that capture and eat
other consumers.
Prey- Organisms that are killed and
consumed by another organism
Mimicry
Mimicry- An organism which looks or acts
like a different species to gain an advantage
for survival.
Mimicry
Plant Herbivore Interactions
Animals that eat plants are known as
herbivores. Ecologists usually classify the
relationship between plants and herbivores
as a form of predation.
Secondary compounds- compounds
produced by plants that are poisonous, bad
tasting or irritating.

Examples- poison ivy, tobacco
Biodiversity
Biodiversity- The number and variety of
organisms in a given area during a specific
period of time.
Primary cause of decreased biodiversity is
habitat destruction.
Climate determines life within a
community.
Climate refers to the prevailing weather conditions
in a given area.
The two most important elements of climate are
temperature and moisture

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Temperature- Most organisms are adapted to live within
a particular range of temperatures.
Moisture- Patterns of rainfall often determine the type
of organisms which live in that location.
Biomes
A major biological community that occurs over a
large area of land is called a biome.
7 major biomes
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tropical rain forest
savannas
taiga
tundra
deserts
grasslands
temperate deciduous forests