Lec 3 Flashcards
ecology
studies how organisms interact with each other and their environment
Ecology is not the same as
protecting the environement
Abiotic:
environmental physical and chemical features
Biotic:
environmental biological factors - organisms interact with others in complex ways
First terrestrial organisms evolved
only about 450 million years ago
unchecked ecological populations grow
exponentially
The largest population size that is sustainable is called
carrying capacity
inhibitors of exponential growth
limited resources & nutrients
competition
mortality & predation
Production:
when an organism generates new resources
Predation:
when an organisms is using other organisms as a resource
Competition:
when a resource is limited some organisms use it at the expense of others
most important biological interaction
production
New resources are generated by
Photosynthesis and Chemosynthesis
Chemosynthesis uses energy from
other chemical comp- ounds instead of the sun
Symbiosis is
when two species live in close association as the result of co-evolution
Commensalism:
one species obtains shelter or food without affecting the other species
Autotrophs get energy from
the non living environment, they are involved in production
Heterotrophs get energy from
other organisms or organic material, they are normally involved in predation but also in production
respiration
The chemical reaction by which heterotrophic organisms obtain energy
In aerobic respiration,
organic molecules are broken down using oxygen (O2), liberating energy, carbon dioxide (CO2) and water (H2O)
Anaerobic respiration and fermentation…
… do not require oxygen but are less efficient
Important mineral nutrients for photosynthesis are
carbon, nitrogen, phosphorus, and iron
resource partitioning
Sometimes species divide the resources and specialize on just part of it
Pelagic:
organisms that live in the water column
Neritic:
pelagic organisms that live above the shelf
oceanic:
organisms that live beyond the shelf break
Plankton:
pelagic organisms that do not swim or swim weakly and are pulled by currents
Nekton:
pelagic organisms that can oppose the current by swimming actively
paleocurrent
currents that bring old organisms that are dead or cannot live there
Tides: limit species that
cannot control desiccation, changes in temperature, wave forces, etc.
