Biology Chapter 5
Terms in this set (21)
the number of individuals per unit area
the number of males and females of each age a population contains
movement of individuals into an area occupied by an existing population
growth pattern in which the individuals in a population reproduce at a constant rate
a population may decrease in size if individuals move out of the population's range
growth pattern in which a population's growth slows and then stops following a period of exponential growth
is the maximum number of individuals of a particular species that a particular enviroment can support
is a factor that controls the growth of a population density
density - dependent limiting factor
limiting factor that depends on population density
density - independent limiting factor
limiting factor that affects all populations in similar ways, regardless of the population density
the scientific study of human population
change in a population from high birth and death rates to low birth and death rates
How do ecologists study populations?
Researchers study populations' geographic range, density and distribution, growth rate, and age structure
What factors afect population growth?
The factors that can affect population size are the birthrate, death rate, and the rate at which individuals enter or leave the population
What happens during exponential growth?
Under ideal conditions with unlimited resources, a population will grow exponentially
What is logistic growth?
Logistic occurs when a population's growth slows and then stops, following a period of exponential growth
What factors determine carrying capacity?
Acting separately or together, limiting factors determine the carrying capacity of an environment for a species
What limiting factors depend on population density?
Density-dependent limiting factors include competition, predation, herbivory, parasitism, disease, and stress from overcrowding
What limiting factors do not typically depend on population density?
Unusual weather such as hurricanes, droughts, or floods, and natural disasters such as wildfires, can act as density-independent limiting factors
How has human population size changed over time?
The human population, like populations of other organisms, tends to increase. The rate of that increase has changed dramatically over time
Why do population growth rates differ among countries?
Birthrates, death rates, and the age structure of a population help predict why some countries have high growth rates while other countries grow more slowly