Click to play Essential Questions What are the factors that effect population growth? What are some of the effects that overpopulation have on an environment?

POPULATION DYNAMICS….7billion & Counting

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Essential Questions

What are the factors that effect population growth?

What are some of the effects that overpopulation have on an environment?

LEVELS OF ORGANIZATIONsmallest unit of living thingsgroup of similar cells organized to work together

group of different kinds of tissues working together

group of organs working togetherone individual living thingall organisms of the same kind living in one area

all interacting populations in an ecosystem

all living and nonliving things interacting within a certain area

large region with typical plants and animals that includes several ecosystems

cell

Population

Dynam

ics

Population Dynamics

How populations change in size due to birth rate/immigration and death rate/emigration and limiting factors ( abiotic and biotic)

Birth Rate:(number of live birth per 1000)

How does death rate

affects population

size?

Death Rate ( number of

death per 1000)

How does death rate

affects population

size?

Immigration: ( movement into an area)

How does immigration

affects population

size?

Emigration:(movement out

of an area)

How does emigration

affects population

size?

Population Size

What goes up must come down

•Increases in population: through birth or immigration

•Decreases in population: through death or emigration.

Change in Population =

Birth Rate +

Immigration

- Death Rate +

Emigration

Logistic or Exponential Growth Curve?

“Boom and Bust” “Boom then stable”

Can you think of something in nature that exhibits exponential growth? Logistic growth?

Population will follow two general paths: • When faced with unlimited resources it will grow exponentially

• When faced with limited resources it grow logistically

Po

pu

lati

on

siz

e (N

)

Time (t)

Carrying capacity (K)

Environmentalresistance

Biotic potential

Exponential growth

• Populations grow rapidly with ample resources (biotic potential), but as resources become limited (environmental resistance), its growth rate slows and levels off

• Carrying Capacity (K) is the maximum number of organism that an area can support

Logistic GrowthCan you think of some resources that could limit population growth? Characterize these resources as abiotic or biotic?

Exponential and Logistic Population Growth: J-Curves and S-Curves

• As a population levels off, it often fluctuates slightly above and below the carrying capacity.

Mung Seed Activity

By the year 2020, 9 to 10 billion humans are expected to inhabit the planet. Do you think the world is overpopulated?

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