RELATIONSHIPS AMONG LIVING THINGS

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RELATIONSHIPS AMONG LIVING THINGS
Day 3
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Interactions Among Living Things

• Living things depend on one another for survival
• An organism may have multiple relationships,
  depending on the organism it interacts with

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Competition

• Can be between same species or different species
• Occurs when resources are limited
• Food
• Water
• Space
• Mate
• Fight occurs in order to gain resources needed

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Predation

• An animal catches and feeds on the captured
  organism
• Predator-hunter
• Prey-hunted

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Symbiotic Relationships MUTUALISM

• Symbiosis-a close relationship between organisms
  that last over a period of time
• Mutualism
• Both organisms benefit from the relationship
• Benefit include food, shelter, protection

Plover and Crocodile
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Symbiotic Relationship PARASITISM

• One species benefits but the other specie gets
  harmed from the relationship
• Benefit can be food, shelter or protection
• Parasite-benefits
• May reside inside (endoparasite) or outside
  (ectoparasite)
• Host-gets harmed
• The parasite has to ensure that the host does not
  die.
• What happens if the host dies?

Mosquito and Human
Tapeworm and Human
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Symbiotic Relationship COMMENSALISM

• A relationship wherein one benefits while the
  other one neither benefits, nor gets harmed or
  dies.
• Commensal- the organism that benefits
• Host- the organism that neither benefits nor gets
  harmed

http//www.youtube.com/watch?vTGRuen6BMbw
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Ecological Relationships EXAMPLES
Video Segments The Secret World of Sharks and
Rays Nature PBS
Video Segments The Secret World of Sharks and
Rays Nature PBS
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Symbiotic Relationships
1. Yellow- billed Oxpecker eating ticks off the
back of a Hippo.
Mutualism 2. Elf Owl and Roadrunner
both trying to eat an insect.
Competition 3. Coral
provides home for algae. Algae produces food for
coral.
Mutualism 4. Tiger hunting a rabbit.
Predation 5. Wasp
lays eggs on Tomato Hornworn caterpillar. Eggs
hatch, burrow into caterpillar and eat it
for food.
Parasitism 6. Red-tailed Hawk builds nest in
branches of Saguaro catcus. Cactus is not
harmed.
Commensalism
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SURVIVAL OF THE FITTEST
What does Survival of the Fittest mean?
Natures way of determining traits needed by an
organism to help its species survive- Natural
Selection
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Natural Selection

• The traits that help an organism survive in a
  particular environment /habitat

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(No Transcript)
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http//app.discoveryeducation.com/search?Nttnatur
alselection
About.com http//science.discovery.com/videos/100
-greatest-discoveries-shorts-natural-selection.htm
l
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The Mono Lake Story
The Mono Lake Story - YouTube
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Is there a relationship which you think is the
best? Why do you say so?
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Picture sources

• susty.com
• thefeltsource.com
• myfourthirds.com
• catalog.beacon-ridge.com
• static.seekingalpha.com
• classes.dma.ucla.edu
• Bcscience.com
• bio.miami.edu

• physicalgeography.net
• webecoist.com
• themain-ingredient.info
• ncwildlife.org
• wikimedia.org