Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

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
population size
total number of individuals in a population
population density
in a population, the number of individuals within the given area
the pattern of distribution of organisms in a population
population model
hypothetical population that attempts to exhibit the key characteristics of a real population
exponetial growth curve
J-shaped curve showing the rapid increase in an exponentially growing population
carrying capacity
population size that an environment can sustain
density-dependent factor
limited resources whose rates of depletion depend on the density of the population using them
logistic model
model of population growth that assumes finite resource levels limit population growth
density-independent factor
facotrs, such as climate, that affect the growth of populations. these facotrs are unaffected by the density of populations
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.
hardy-weinberg principle
principle stating that the frequency of alleles in a population does not change unless evoultionary forces act on the population
gene flow
movement of alleles in or out of a population due to the migration of individuals to or from the population
nonrandom mating
mating between individuals of the same phenotype or by those who live nearby
genetic drift
random change in allele frequency in a population
polygenic trait
charcteristic of an organism that is influenced by several genes
normal distribution
bell-shaped curve that results when the values of a trait in a population are plotted against their frequency
directional selection
natural selection that causes the frequency of a particular allele to move in one direction
stablizing selection
type of natural selection in which the average form of the trait is favored and becomes more common