Ecological Relationship Notes

Mutualism (Symbiosis) – Both species benefit
o Ex. Bees and Flowers, Cows and cellulose digesting bacteria, clownfish and sea anemone

Commensalism – One species benefits while the other is neither hurt nor helped
o Ex. Birds and Army ants, sharks and little fish swimming below them,

Predation – One organism feeds on the other
o Ex. Any predator / prey relationship…. Killer whale / sea lion, Humans / cows

Parasitism – One organism feeds off the other, but the other stays alive
o Ex. Ticks, mosquitoes, some bacteria, fungi

Parasitoid – One organism lays its eggs in the other. The infected organism then becomes a host
that the larvae will use as a food source
o Wasps and Caterpillars

Competition – Organisms competing for the same mates, habitat, and / or food
o Intraspecific competition –Competition within a species
 Ex. Male deer fighting for mates
o Interspecific competition – 2 different species competing for food or habitats
 Ex. Scorpions and spiders
Mimicry
o Batesian mimicry - a form of mimicry typified by a situation where a harmless species
has evolved to imitate the warning signals of a harmful species directed at a
common predator.
o Mullerian mimcry - natural phenomenon in which two or more poisonous species, that
may or may not be closely related and share one or more common predators, have
come to mimic each other's warning signals.

Levels of Organization (Life’s Hierarchy)
Least specific
 Biosphere – All environments on Earth that support life
(Basically, the Earth and the sky
above it that has living things occupying it.)
 Biomes – A group of ecosystems that have similar climates and communities
 Ecosystem – all living organisms in a particular area as well as the nonliving, physical
components they interact with (ex. Sunlight, water, etc.)
 Community – All living things in an area
 Population – Single species living in a single area
 Organism – Single individual
 Organ System – group of organs working together for a certain function
 Organ – 1 part of an organ system
 Tissue – group of similar cells that do a particular function for an organ
 Cell – Smallest unit of life (All living things are made of up of one or more cells)
 Organelle – “organ” of a cell
 Molecule – cluster of atoms held together by chemical bonds
 Atom - basic unit of matter made of dense nucleus (protons and neutrons) with electron cloud
around it
Most specific
Levels of Organization (Life’s Hierarchy)
Least specific
 Biosphere – All environments on Earth that support life
(Basically, the Earth and the sky
above it that has living things occupying it.)
 Biomes – A group of ecosystems that have similar climates and communities
 Ecosystem – all living organisms in a particular area as well as the nonliving, physical
components they interact with (ex. Sunlight, water, etc.)
 Community – All living things in an area
 Population – Single species living in a single area
 Organism – Single individual
 Organ System – group of organs working together for a certain function
 Organ – 1 part of an organ system
 Tissue – group of similar cells that do a particular function for an organ
 Cell – Smallest unit of life (All living things are made of up of one or more cells)
 Organelle – “organ” of a cell
 Molecule – cluster of atoms held together by chemical bonds
 Atom - basic unit of matter made of dense nucleus (protons and neutrons) with electron cloud
around it
Most specific