Transcript 14.2 Community Interactions

14.2 Community Interactions
KEY CONCEPT
Organisms interact as individuals and as populations.
14.2 Community Interactions
Competition and predation are two important ways in
which organisms interact.
• Competition occurs when two organisms fight for the
same limited resource.
– Food
– Water
– Shelter
– Mates
• How does cooperation
and competition among
organisms differ from
human cooperation and
competition?
14.2 Community Interactions
Interspecific competition
• Occurs between two different species, even though they
have different niches
14.2 Community Interactions
Intraspecific Competition
• Occurs between members of the same species.
14.2 Community Interactions
• Predation occurs when one organism captures and eats
another.
14.2 Community Interactions
Predation
14.2 Community Interactions
Symbiosis - A close relationship between 2 or more
organisms of different species living together
14.2 Community Interactions
• There are three major types of symbiotic relationships.
1. Mutualism: both organisms benefit
14.2 Community Interactions
Lesser long nosed bat
• Bat pollinates cactus
in spring as they feed
on nectar
• In summer eat fruit
and spread
indigestible seeds
when they pooh!
14.2 Community Interactions
Can you think of other mutualism examples
14.2 Community Interactions
• There are three major types of symbiotic relationships.
2. Commensalism: one organism benefits, the other is
unharmed
Ø
Human Our eyelashes
are home to tiny mites
that feast on oil
secretions and dead
skin. Without harming
us, up to 20 mites may
be living in one eyelash
follicle.
Commensalism
Ø Organism is not affected
+
+
Organism benefits
Demodicids Eyelash
mites find all they need to
survive in the tiny follicles
of eyelashes. Magnified
here 225 times, these
creatures measure 0.4
mm in length and can be
seen only with a
microscope.
14.2 Community Interactions
Commensalism
14.2 Community Interactions
• There are three major types of symbiotic relationships.
3. Parasitism: one organism benefits, the other is harmed
0 Braconid
wasp
+ Braconid
larvae feed
on their host
and release
themselves
shortly before
reaching
the pupae
stage of
development.
Parasitism
_
Hornworm
caterpillar
The host
hornworm will
eventually die as
its organs are
consumed
by wasp larvae.
_
Organism is not affected
0
Organism
benefits
14.2 Community Interactions
• There are three major types of symbiotic relationships.
– 3. Parasitism meet their needs as ectoparasites
(such as leeches) and endopaasites (such as
hookworms)
14.2 Community Interactions
Worst parasites
Parasites
Pinworms – Yikes!