RELATIONSHIPS AMONG LIVING

THINGS

Day 3

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

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

Predation

• An animal catches and feeds on the captured organism

• Predator-hunter• Prey-hunted

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

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

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?v=TGRuen6BMbw

Video Segments: The Secret World of Sharks and Rays | Nature | PBS

Ecological Relationships:EXAMPLES

Video Segments: The Secret World of Sharks and Rays | Nature | PBS

Symbiotic Relationships:

1. Yellow- billed Oxpecker eating ticks off the back of a Hippo. Mutualism2. Elf Owl and Roadrunner both trying to eat an insect. Competition3. Coral provides home for algae. Algae produces food for coral. Mutualism4. Tiger hunting a rabbit. Predation5. Wasp lays eggs on Tomato Hornworn caterpillar. Eggs hatch, burrow into caterpillar and eat it for food. Parasitism6. Red-tailed Hawk builds nest in branches of Saguaro catcus. Cactus is not harmed. Commensalism

What does “Survival of the Fittest” mean?

SURVIVAL OF THE FITTEST

Nature’s way of determining traits needed by an organism to help it’s species survive- Natural Selection

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

About.com: http://science.discovery.com/videos/100-greatest-discoveries-shorts-natural-selection.html

http://app.discoveryeducation.com/search?Ntt=natural+selection

The Mono Lake Story

The Mono Lake Story - YouTube

Is there a relationship which you think is the best? Why do

you say so?

Is there a relationship which you think is the best? Why do

you say so?

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