Post on 12-May-2018
Ch 4: Population Biology
4.1 Population Dynamics
Section 4.1
Linear vs. Exponential Growth
Carrying Capacity
Reproductive Strategies
Limiting Factors
Inside This Section...
Lets Calculate the number of bacteria there would be if the population were allowed to grow for 24 hours.
Assume that there were two to start with, they divide once every 20 minutes, and none of them died.
What factors might keep them from taking over the world?
Logical Mathematics
Section 4.1
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________ Growth
Suppose you work at a some job
You get paid $10 per hour
How much would you have in 10 hours?
Section 4.1
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Linear vs. Exponential Growth
______________ Growth
The initial phase of population growth is slow because the number of available organisms is ________ at first.
Soon the growth becomes very fast as the organisms ____________.
Linear vs. Exponential Growth
Section 4.1
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375
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2nd
3rd
4th
5th
6th
7th
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9th
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Can a population of organisms grow indefinitely?
__________________
Space to grow
Availability of food
The number of organisms that an environment can support is called the ____________________.
Limits of the Environment
Section 4.1
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The graph of the carrying capacity is a _________.
Populations start out slow and then experience a period of _____________ growth, followed by a ____________ growth rate.
Populations go above the average line then fall below, only to rise above again.
Carrying Capacity
Section 4.1
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19Population Carrying Capacity
Why do some populations of organisms seem to thrive at certain times of the year and then dwindle at other times?
In order to answer this question biologists study the _______________ cycles of animals.
Patterns of Population Growth
Section 4.1
Two extreme organisms for population growth rates are elephants and mosquitoes.
Mosquitoes are ______ reproducers over a ________ time.
Elephants are ______ reproducers over a ______ time.
Ranges of Population Growth
Section 4.1
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Mosquitoes are successful in environments that are ________________ and __________.
Organisms with this type of life-history pattern tend to:
Be ______
Mature ________
Reproduce ______
Have a ______ life span
The Mosquito Strategy
Section 4.1
Organisms that tend to live in a more _______ environment have a different life-history pattern. They tend to:
Be ______
Reproduce and mature _______
Live for ______ periods of time.
The Elephant Strategy
Section 4.1
The type of reproductive cycle that an animal has depends on the ______________ they are in.
Why the Different Types of Reproductive Cycles?
Section 4.1
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Density-____________
E.g. Disease, Competition, Parasites, Food
(effects get bigger as population size ___________)
Density-_____________
Temperature, Storms, Floods, Drought
(effects not influenced by population size – mostly _______)
Two Types of Limiting Factors
Section 4.1
The population of the prey in a community will affect the population of the ____________.
Likewise the opposite is true.
This relationship is referred to as the _________________ ______________
e.g. Lynx and Hare
Predation Affects Population
Section 4.1
The more organisms you have struggling for the same resource the _____ resources there are for each individual organism.
Competition for Resources
Section 4.1
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As a population grows the amount of stress increases in a population.
Stress can cause:
_____________
Decrease in ___________ care
Decreased __________
Decreased resistance to ___________
Crowding and Stress
Section 4.1
Section 4.1
In Review...
Linear vs. Exponential Growth
Carrying Capacity
Reproductive Strategies
Limiting Factors
4.2 - Human Population Growth
Ch 4: Population Biology
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Section 4.2
Demography
Growth Rate, Age Structure and Geographic Distribution
Inside This Section...
Demographics is the study of human population growth and characteristics.
Demographics are concerned with:
______________
________________
___________________________
Demographics can be used as tools to predict future population tendencies.
Demography
Section 4.2
A populations growth rate is measured by finding the difference between the _____ rate and the ______ rate.
If a country’s birth rate is 38.5/1000 and it’s death rate is 21/1000, what is their growth rate?
Birth Rates & Death Rates
Section 4.2
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The amount of time that it takes for a population to ________ in size.
DT = 70/the annual growth rate
Doubling Time
Section 4.2
Age structure refers to the proportions of a population that are at different _____ _______.
If it is equal at different levels, this results in a _______ population.
This is useful in making _____________.
Age Structure
Section 4.2
Finland - 2006
_____________: Movement of individuals into a population
____________: Movement from a population
Immigration and emigration has no effect on total world population, but does affect __________ growth rates. Also affects _______ populations
Mobility
Section 4.2
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