Download Ecology

Molecules:
 Groups of atoms held together by
bonds; smallest unit of most chemical
compounds
Many complex molecules can be
organized into
Cells:
 Smallest functional unit of life
Groups of Cells can be further organized
into
 Tissues, organs, and organ systems
Nervous tissue
Brain
Nervous system
Organisms: Can by pass certain levels to
be made up of a single cell, many
specialized tissues, or many organ
systems
 Individual living thing
Population:
 Group of organisms of one type that live
in the same area
 One Type?
 Species: Any organisms that have the
ability to reproduce with each other, and
those offspring can reproduce as well.
Community:
 Populations that live together in a
defined area
Ecosystem:
 Community and its nonliving
surroundings
Biosphere:
 The part of Earth that contains all
ecosystems
Eco = House; Logos = Study
The scientific study of the interactions
among organisms & between organisms
and their environment.
New science (1976), but not really.
Vast discipline which includes:
 Biology (zoology, botany, mycology, etc)
 Geology
 Meteorology
 Genetics
 Chemistry
 Physics
Biotic Factors: All the living components
Abiotic Factors: All non-living components
Environments are different b/c of different
abiotic factors.
These different abiotic factors shape what
type of biotic factors can inhabit that
environment.
Biosphere
Biome
Ecosystem
Community
Population
Individual
 Population
Density
 Population Distribution
 Population Growth
The number of individuals per unit of area.
 How dense a population gets depends on
species (Bacteria vs. Grizzly bears) as
well as abiotic factors of ecosystem.
The size of a population
fluctuates greatly
depending on 4 main
factors.
Natality = Birth rate (+)
Mortality = Death rate ()
Immigration =
Migration into a pop
(+)
Emigration = Migration
out of a pop (-)
When natality > mortality and/or
immigration > emigration a population
will grow in size.
Patterns
1. Exponential Growth: occurs when
individuals in a population reproduce at
an Increasing rate.
•
This results in a “J-shaped” curve when you
plot the number of individuals over time.
When would a population display
exponential growth?
Realistically, resources are limited, and as a
pop gets bigger those resources become
more limited and growth slows, stops, or
shrinks.
2. Logistic Growth: When a popualtion
grows exponentially at first them slows
or stops due to limiting resources.
Results in a “S – Shaped” curve.
Carrying Capacity: The largest number of
individuals that an environment can
support.
 Not fixed; can fluctuate based on
conditions of environment.
 Can vary between different populations
of same species, or between different
species.
Limiting Factors: Factors that cause a
population growth rate to slow or stop
resulting in that pop reaching it’s carrying
capacity.
2 types:
1. Density-dependent: Limiting factors whose
affect is dependent on pop density ( as
pop gets bigger the effect is greater)
 Ex. Predation, disease, competition with
other members of pop.
2. Density-independent: Limiting factors that
effect growth rate regardless of how dense
pop is.
 Ex. Drought, storms, temp.,