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46.1 Scope of ecology
  • Ecology is the study of the interactions of organisms with other organisms and with the physical environment.
  • The interactions of organisms with the abiotic and biotic environment affect their distribution and abundance.
  1. Distinguish between population, community and ecosystem.
    Answer
  2. What is the difference between the density and distribution of a population?
    Answer
  3. Things in the environment that are required for a particular species and that can determine their presence or absence in an area are called ________________.
    Answer
Essential Study Partner Summaries of major points
  1. Ecology
  2. Density and distribution of populations
Art Review
46.2 Characteristics of populations
  • Population size is dependent upon natality, mortality, immigration, and emigration.
  • Population growth models predict changes in population size over time under particular conditions.
  • Mortality within a population is recorded in a life table and illustrated by a survivorship curve.
  • Populations have an age distribution consisting of prereproductive, reproductive, and postreproductive portions.
  1. What factors determine the size of a population?
    Answer
  2. What do we mean when we say that the intrinsic rate of increase of a population is per capita?
    Answer
  3. What are discrete and continuous breeding populations?
    Answer
  4. What is biotic potential and under what kind of population growth is it observed?
    Answer
  5. Conditions in the environment which prevent populations from attaining their biotic potentials are called ________________.
    Answer
  6. What type of population growth occurs in the presence of environmental resistance?
    Answer
  7. What is carrying capacity?
    Answer
  8. Which kind of population will grow faster, one with more males than females or one with more females than males, and why?
    Answer
Essential Study Partner Summaries of major points
  1. Population size
  2. Population growth models
  3. Exponential growth
  4. Logistic growth
  5. Carrying capacity
  6. Mortality patterns
  7. Age distributions
Art Review Art Quizzes Animations
(To play the animation, lengthen the pop-up window until the control bar appears.) Animation Quizzes Lab exercises
46.3 Regulation of population size
  • Factors that affect population size are classified as density-independent factors and density-dependent factors.
  1. What are the differences between density-independent and density-dependent factors of population growth?
    Answer
  2. True or False: Population size grows in a smooth curve to the carrying capacity and then levels off and stays level.
    Answer
Essential Study Partner Summaries of major points
  1. The J-shaped and S-shaped growth curve models...
  2. Populations do not increase in size year after year because...
Art Review
46.4 Life history patterns
  • Life histories range from discrete reproductive events resulting in rapid population growth to repeated reproduction resulting in a stable population size.
  1. What are the characteristics of a population of r-strategists?
    Answer
  2. Organisms with long life spans, slow rates of growth, and parental care of only a few young at a time are under what type of selection?
    Answer
  3. In what type of environments do r-strategists and K-strategists each do best?
    Answer
Essential Study Partner Summaries of major points
  1. The logistic population model predicts...
  2. Most populations cannot....
Art Review
46.5 Human population growth
  • The human population is still growing exponentially, and how long this can continue is not known.
  1. What type of growth curve is the human population currently experiencing and what is its doubling time?
    Answer
  2. What is the difference in the age structure of more-developed and less-developed countries and what does this mean for future population growth in those countries?
    Answer
  3. How is environmental impact of human populations calculated?
    Answer
  4. What are the differences in environmental impact between less-developed and more-developed countries?
    Answer
Essential Study Partner Summaries of major points
  1. The human population is growing
  2. More-developed vs. less-developed countries
  3. Comparing age distributions
  4. A sustainable world
Art Review Art Quizzes Animations
(To play the animation, lengthen the pop-up window until the control bar appears.) Animation Quizzes







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