Chapter 52 Test

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  1. Population Ecology
    the study of populations and interactions with their environment
  2. Population
  3. groups of organisms of the same species occupying a defined area at a specific time
  4. Characteristics of populations (5)
    • Birth Rate
    • Death Rate
    • Age Structure
    • Sex Ratios
    • Density
  5. Birth Rate
    # of births/individuals born/unit time
  6. Death Rate
    • # deaths/ #individuals/year
    • Mortality rate is the number of individuals in a population dying during any given time interval divided by the number alive at the beggining of the time interval
  7. Age Structure
  8. distribution of numbers of individuals of various ages
  9. Sex ratios
  10. ratio of number of males to number of females
  11. Denisty
    # individuals/unit area
  12. Birth Rate and immigration often,..
    increase populations
  13. Mortality and emigration often...
    decrease populations
  14. Hos is birth rate often expressed?
    number of offspring/female/year or per 100 females/year
  15. What is the denisty dependent factor
    factor that takes a varying % of the population depending on the density of the population (competition, predation, crowding, parasites, disease)
  16. What is the density independent factor?
    factor that takes a constant % of the population independent of pupulation density (climate and weather, shortage of resources-nest sites, den sites, etc, non infections diseases, pollution)
  17. What is exponential population growth?
    growth under no environmental resistance or limiting factors
  18. Environmental resistance
    competition and its effects of food, cover, space and water resources, predation (interspecific competition), disease, starvation, etc
  19. What do we have to assume with exponential growth?
    that there are no limits such as predation, diseases, etc
  20. Characteristics of exponential growth
    • population grows at increasing rates
    • "j curve" depicts population growth at increasing rates
  21. Does exponential growth last?
    • usually no, environment is not constant and resources are limited
    • birth rates will decline, death rates will increase, or both to even out once K is reached
  22. Logistic population growth
    • biotic potential of the population is held in check or limited by environmental resistance
    • biotic potential is synonymous with reproductive potential, maimum rate of population increase under ideal conditions
  23. In Logistic pop growth
    • environmental resistance dictates the carrying capacity of the area or habitat
    • there is an S curve graph
  24. What is Carrying Capacity?
    the number of animasl an area can support over a period of time without damage to that habitat
  25. What are reproductive strategies
    • the more energy spent on reproduction, the less energy it can distribute for growth and maintenence
    • investment includes not only the production of offspring but also care and nourishment
    • species in different environments will differ in life history traits such as size, productivity, age at first reporduction, # of reproductive events during lifetime, and total life span
    • r and k selection
  26. What is r seleciton?
    • selection under low population densities
    • many offspring
    • favors high reproductive rates under conditions of low competition
    • fish, bugs, etc
  27. What classifies an r strategist?
    • variable climate
    • density independent mortality
    • variable pop size
    • short life span
    • rapid development
    • high rate of increase
    • early reproduction
  28. What is K selection?
    selection under carrying capacity conditions and a high level of competition
  29. What classifies a k strategist?
    • stable climate
    • density dependent
    • constant pop size
    • long life span (>1year)
    • little offspring
    • reproduce less often
    • slow development
    • low rate of increase
    • larger offspring
  30. Clumped dispersion?
    • clumped together populations
    • most common type of dispersion
    • ex: packs of wolves, elephants, etc
  31. Uniform Dispersion?
    evenly spread out, very specific
  32. Random Dispersion
    • random spacing and distribution
    • ex: flower pollen, tree seeds, etc
  33. Population growth equation
    • dN/dt= riN
    • =N(m-b)

    • N- number of individuals
    • ri- max growth rate, intrinsic growth rate
    • t- time
    • d- rate of change
    • b- birth rate
    • m-mortality rate
  34. What are survivorship curves? what different kinds?
    • survivorship curves are graphs showing the survival and reproduction of populations
    • Types 1,2, and 3
  35. Type 1 survivorship curve?
    • like k selection
    • few offspring, but live long time
    • high mortality rate towards post reproduction years
    • ex: humans
  36. Type 2 survivorship curve?
    • constant mortality rate throughout life
    • ex: Hydra
  37. Type 3 survivorship curve?
    • like r selection
    • many offspring, but many die close to birth
    • few lucky ones survive a longer time
    • high mortality rate at pre reproduction years
  38. Semelparity?
    • Reproduces once before death
    • k selected
    • ex: bears
  39. Iteroparity
    • reproduce ofthen througought life
    • r selected
    • ex:fish
  40. how do limited resources and trade offs affect life histories?
    limited resources can cause the pop to decrease and the fit survive and trade offs have organisms with low survival rate produce many offspring for a chance and organisms with a higher survival rate produce fewer organisms
  41. Exponental growth equation
  42. Logistic Growth equation
    dN/dt=rN x (k-n)/k
Card Set
Chapter 52 Test
Test of 9/21/2011
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