LIVING THINGS AND THE ENVIRONMENT

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In this unit you will learn about how to
Analyze how ecosystems differ from each other due
to abiotic and biotic factors.
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LIVING THINGS AND THE ENVIRONMENT
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A prairie dog is one type of organism.
Each organism must live in a specific type of
environment.
An organism obtains food, water, shelter, and
things it needs to live, grow, and reproduce from
its environment.
An environment that provides the things the
organism needs to live, grow and reproduce is
called its habitat.
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An organism interacts with both the living and
nonliving parts of its habitat.
The living parts of a habitat are called
____________.
biotic factors
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The nonliving parts of an organisms habitat are
called ____________.
abiotic factors
Abiotic factors include
-water
-sunlight
-oxygen
-temperature
-soil
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ECOLOGICAL ORGANIZATION
Population (prairie dog town)
Organism (prairie dog)
Community (all the living things that interact on
the prairie)
Ecosystem (all the living and nonliving things
that interact on the prairie)
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CHANGES IN POPULATION SIZE
Population can change in size when new members
join the population or when members leave the
population.
BIRTH RATE
The number of births in a population in a certain
amount of time.
DEATH RATE
The number of deaths in a population in a certain
amount of time.
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CHANGES IN POPULATION SIZE
Population increases
If birth rate gt death rate
Population decreases
If death rate gt birth rate
Population Stays the same
If death rate birth rate
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POPULATION DENSITY
- The number of individuals in a specific area.
What is the formula to calculate population
density?
Number of individuals
_____________
Population Density
Unit Area
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Calculate the population density of flamingos.
10 flamingos
Population Density
___________


1.25
Flamingos/ square meter
8 square meters
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Calculate the population density of flamingos.
20 flamingos
Population Density
___________


2.5
Flamingos/ Square meter
8 square meters
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The largest population an area can support is
called its ____________.
carrying capacity
The carrying capacity of a population is
determined by limiting factors.
Limiting factor
An environmental factor that causes a population
to decrease.
food
water
space
weather conditions