Download Interactions Among Living Things

Warm Up
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From last week’s activity – How could the
disappearance of wolves from the ecosystem
affect the population of other species?
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Video clip
Warm Up
1. How do these organisms interact with each
other?
Warm Up
2. How do these organisms interact with each
other?
Warm Up
3. How do these organisms interact with each
other?
Types of Interactions Among
Living Things
Interactions with the Environment
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
Most living things produce more offspring
than will survive. This is known as
overproduction.
So why are we not overrun with frogs or fish?
Limiting Factors
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Organisms interact with the biotic & abiotic factors in
their environment.
Populations cannot grow without stopping.
Limiting factor – a resource that is so scarce that it
limits the size of a population.
Limits on the amount of: (examples)
–
–
–
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Food
Water
Living space
Other resources
Carrying Capacity
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Carrying capacity – the largest population that an environment
can support.
When a population grows larger than its carrying capacity,
limiting factors in the environment cause individuals to die off or
leave, returning the population to a size that the environment
can support.
Interactions Among Organisms
1.
2.
3.
Competition
Predation
Symbiosis
Adaptations

Every organism has a variety of adaptations (characteristics)
that are suited to its specific conditions which help the organism
to survive.
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The adaptations can also assist them in their interactions with
other organisms.
1. Competition

Competition – when two or more individuals or
populations try to use the same resources.
–
Compete for:
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Food, water, shelter, space, sunlight
Adaptations enable organisms to reduce competition.
Competition in a Population
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Example:
–
The elks in Yellowstone National Park are
herbivores that compete with each other for food
plants in the park.
Competition in a Community
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Example:
–
Competition also happens between different
populations (within a community).

Different species of plants compete with each other for
sunlight and space.
2. Predation

An interaction in which one organism hunts
and kills another organism for food is called
predation.
–
Predator

–
the hunter
Prey

the hunted
Video clip: predatorprey
Predator Adaptations
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Helps them catch & kill their prey
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Speed
Stingers, toxins, sharp teeth
Camouflage
Night vision
Prey Adaptations
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Also known as “defense strategies” to avoid
predation:
1.
2.
3.
4.
5.
6.
Camouflage
Protective coverings
Warning coloring
Defensive chemicals
Mimicry
False coloring
Camouflage
Prey blend in to their
environment to avoid being
eaten by predators.
Protective Coverings
Hedgehog
Warning Coloring
Bright colors warn predators that the
prey may be poisonous and to stay
away!
Defensive Chemicals
Some animals defend
themselves with
chemicals.
Mimicry
The ability some animals have
to resemble another animal so
closely that they can fool either
their prey or their predators.
Monarch
Coral Snake
Viceroy
King Snake
False Coloring
Used to trick predators
With your table group…
 Describe
the 2 relationships
among living things we
discussed yesterday…
3. Symbiosis
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Symbiosis is a close relationship between
two species that benefits at least one of the
species.
3 types:
1.
2.
3.
Mutualism
Commensalism
Parasitism
Mutualism
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A relationship in which both species benefit
–
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Positive
Ex:
–
clownfish & sea anemone
Commensalism
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A relationship in which one species benefits
and the other is neither helped nor harmed
–

Neutral
Ex:
–
gray whale
covered in
barnacles
Parasitism
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Involves one organism living on or inside
another organism and harming it!
–
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Negative
Parasite – the organism that benefits
Host – the organism that is harmed
Ex:
–
Tapeworms
“Who You Callin’ Ugly?”
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Do you think it is beneficial for each of these
organisms to look they way they do? Why or
why not?
“Who You Callin’ Ugly?”
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What is an adaptation?
Read the article

Complete the following chart as a group:

Animal:
Proboscis Monkey
Leaf-Tailed Gecko
Wrinkle-Faced Bat
Star-Nosed Mole
Marabou Stork
Sea Pig
Odd or interesting
trait:
How is this trait
beneficial to the
animal?