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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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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Section 4.2

Demography

Growth Rate, Age Structure and Geographic Distribution

In Review...

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