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20 Cards in this Set

  • Front
  • Back
group of individuals that belong to the same species, live in the same area, and breed with others in the group
total number of individuals in a population
population size
in a population, the number of individuals in a given area
population density
the pattern of distribution of organisms in a population
hypothetical population that attempts to exhibit the key characteristics of a real population
population model
J-shaped curve showing the rapid increase in an exponentially growing population
exponential growth curve
population size that an environment can sustain
carrying capacity
limited resources whose rates of depletion depend on the density of the population using them
density-dependent factors
model of population growth that assumes finite resource levels limit population growth
logistic model
factors, such as climate, that affect the growth of populations. These factors are unaffected by the density of populations
density-independent factor
species characterized by rapid growth, high fertility, short lifespan, and exponential population growth
species characterized by slow maturation, few young, slow population growth and reproduction late in life
principle stating that the frequency of alleles in a population does not change unless evolutionary forces act on the population
Hardy-Weinberg principle
movement of alleles into or out of a population due to the migration of individuals to or from the population
Gene flow
mating between individuals of the same phenotype or by those who live nearby
Nonrandom mating
random change in allele frequency in a population
genetic drift
characteristic of an organism that is influenced by several genes
polygenic trait
bell-shped curve that results when the values of a trait in a population are plotted against their frequency
normal distribution
natural selection that causes the frequency of a particular allele to move in one direction
directional selection
type of natural selection in which the average form of the trait is favored and becomes more common
stabilizing selection