Download Interactions Among Living Things

Interactions Among Living
Things
A 7th Grade science presentation
Interactions
 There are three major interactions
among organisms:
 Competition
 Predation
 Symbiosis
Predation
 Predation is an interaction in which one organism
kills and eats another organism.
 The organism that does the killing is the predator.
 The organism that is killed is the prey.
 Predation can have a major effect on the size of a
population.
Competition
 Competition is the
struggle between
organisms to
survive in a habitat
with limited
resources.
Symbiosis
 Symbiosis is a close relationship
between two species that benefits at
least one of the species
 There are three types of symbiotic
relationships:
 Mutualism
 Commensalism
 Parasitism
Mutualism
 mutualism is an interaction
between two or more species
where both species derive
benefit.
 Ant-aphid mutualism: the
aphids are protected from
predators by the ants. The
ants get the aphid secretion of
honeydew as a reward.
Commensalism

Commensalism—is a relationship in which one species
benefits and the other species is neither helped nor
harmed.

The Remora fish (Echeneidea) is a long slender fish which has its
dorsal fin modified as a sucker-like attachment organ. It attaches
to the sides of larger fish and turtles using them as transport hosts
but in addition, obtains food fragments dropped from the host.
Parasitism
 An organism living on or inside
another organism and harming
it.
 Head lice
 Ticks
 Fleas
 Heart worm
Tape Worm
Athlete’s foot
Ring worm
Parasitism
 The organism that benefits is called a
parasite.
 The organisms that it lives on or in is
called a host.
Thank you
 For paying attention and taking
notes.
 This concludes the slide show.