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20 Cards in this Set
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What factors affect population size?

birth rate
immigration rate death rate emigration rate 

What is the exponential growth model?

The exponential growth model describes population growth in an ideal environment.


What is carrying capacity?

Carrying capacity (k) is the maximum population size that a specific environment can support.


Which factors determine "k" for a habitat supporting an elephant population?

rain fall
nutrients, minerals, mineral salts disease parasitism predation 

What is the densitydependent (logistic) growth model?

The densitydependent (logistic) growth model accounts for the reduced growth rate as a population approaches the carrying capacity (k) of its environment.


When does a population stop increasing in a densitydependent (logistic) growth model?

A population theoretically stops increasing when it reaches its carrying capacity.


When should the exponential model NOT be used?

The exponential growth model should not be used when the population has a defined carrying capacity.


When should the logistic model be used?

The logistic model should be used when a habitat has a defined carrying capacity.


Which model accounts for the reduction in growth rate that occurs when a population approaches the carrying capacity of its environment?

the logistic model


What is the only factor that limits growth in an ideal environment (exponential growth model)?

Maximal reproductive rate is the only factor that limits growth in an ideal environment.


Densitydependent factors affect birth and death rate.
Increasing density usually results in 
reduced birth rate
increased death rate 

What are the causes of densitydependent regulation?

competition among individuals for limited food
infectious disease and parasitism predation accumulation of toxic metabolism wastes 

Increased stress at high density reduces

birth rate
effective parenting behavior immune system difficiency 

As population density increases, birth rate _______.

decreases


As population density increases, death rate ________.

increases


What is the common equation for computing a change in population size?

∆N/∆t = r x N


What does ∆N stand for?

the change in population size


What does ∆t stand for?

the time interval


Which factors determine the carrying capacity of an environment?

food availability, space, predation, etc.


How do metabolic waste products affect the growth rate of microbial populations?

Microbial growth rates decline as their output of metabolic wastes increases at high densities.
