Card Set Information

2010-07-15 04:23:50

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  1. population
    group of individuals all of the same species living in the same area
  2. community
    group of populations living in the same area
  3. ecosystem
    interrelationships between the organism in a community and their physical environment
  4. biosphere
    all the regions of the earth that contain living things.
  5. habitat
    • where an organism usually lives
    • may include physical and chemical environment
  6. niche
    • all the biotic (living) and abiotic (nonliving) resources in the environment used by an organism
    • certain resources being consumed or certain qualities of life are changed in some way by the presence of the organism
  7. population ecology
    study of the growth, abundance, and distribution of populations
  8. size
    • represented by N
    • total number of individuals in a population
  9. density
    total number of individuals per area or volume occupied
  10. dispersion
    • how individuals in a population are distributed
    • may be: clumped, random, uniform
  11. age structure
    • abundance of individuals of each age
    • horizontal:expresses the frequency of individuals in an age group
    • vertical line:divides each age group into males and females
    • rapid growing:large portion of the population is young (pyramid shaped)
    • when tiers are equal=zero (stable) population growth
  12. survivorship curve
    how mortality of individuals in a species varies during their lifetimes
  13. Type I (survivorship curve)
    species in which most individuals survive to middle age. after that age, mortality is high
  14. Type II (survivorship curve)
    • length of the survivorship is random
    • likelihood of death is the same at any age
  15. Type III (survivorship curve)
    • most individuals die young
    • few survive to reproductive age or beyond
    • ex: oysters, plankton