Ecology- Bio Test 3

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  1. ecology
    the study of relationships among organisms and between organisms and their environment
  2. population
    a group of individuals from the same species that share the same habitat, share the same resources, and potentially interbreed
  3. demography
    the measurement and statistical study of characteristics of populations
  4. characteristics of populations
    • size
    • density
    • dispersion
    • age structure
    • sex ratio
    • natality and mortality
  5. size
    • total number of individuals 
    • if population size is constant, then... b+i=d+e
    • b=births
    • i=immigration
    • d=deaths
    • e=emigration
  6. density
    number of individuals per unit area
  7. dispersion
    • how the individuals are spaced
    • three types: random, uniform, clumped
  8. natality
    • birth rate
    • each individual has a total reproductive value (TRV)
    • natural selection favors the life-history with the greatest TRV or sum of CRV and RRV
  9. TRV=...
    CRV+RRV where CRV is current reproductive value and RRV is residual reproductive value
  10. 3 key life history characteristics or adaptations that influence natality
    • 1) age at first reproduction
    • 2) litter or clutch size
    • 3) reproductive events per lifetime
    • -semelparity vs. iteroparity
  11. life tables
    illustrate the likelihood of survival at any given age
  12. survivorship
    type I, type II, type III
  13. factors affecting population growth
    • sex ratio
    • generation time
    • age structure- the proportion of individuals in each cohort
  14. population
    a group of organisms of a single species inhabiting the same geographic area
  15. community
    a group of populations inhabiting the same geographic area
  16. niche
    each species in a community plays a unique role in the structure and function of the community
  17. Lotka and Voltera
    • based on equations derived by them, Gause argued that two species cannot occupy the same niche
    • -Lotka-Voltera equations
    • -Gause's principle of competitive exclusion
  18. fundamental niche
    the niche an organism is theoretically capable of occupying or using
  19. realized niche
    the actual niche that an organism occupies due to interactions with other species in the community
  20. intraspecific
    • intra=within
    • within a species
  21. interspecies
    • inter=between
    • interspecific- between species
  22. possible population-level responses to interspecific interactions
    • 1. positive
    • 2. negative
    • 3. neutral
  23. possible outcomes of interspecific interactions
    • +,+ mutualism
    • +,- predation
    • +,0 commensalism 
    • -,- competition
    • -,0 ammensalism 
    • 0,0 neutralism (most common)
  24. predation
    one of the best studied interspecific interactions
  25. why have organisms evolved several types of defense mechanisms?
    because of the extreme selective pressure
  26. physical plant defense mechanisms
    • thorns
    • spines
    • silica
  27. competition occurs when...
    • the niches of two organisms overlap
    • 2 types: interference, exploitative 
    • MacArthur's Resource Partitioning hypothesis
  28. symbiosis
    • when two or more dissimilar species live together in close association
    • e.g., commensalism, mutualism, and parasitism
  29. community characteristics
    • 1. species composition 
    • 2. species diversity
    • -richness
    • -evenness
    • 3. relative abundance of species
    • 4. spatial and temporal distributions of species
Card Set:
Ecology- Bio Test 3
2013-11-16 23:25:16

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