bio quiz2

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bio quiz2
2010-11-03 01:34:45

bio 110
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  1. Traits are expressed at an..
    Individual level
  2. Evolution happens at a...
    Population level
  3. Evolution
    Change in the allele frequency of a population over time
  4. Natural populations
    are always evolving, which means that allele frequencies in their gene pool are always changing over generations.
  5. Mutation is the source of new alleles
  6. GE: #1
    No mutations
  7. GE: #2
    The population is infinitely large
  8. GE: #3
    The population is isolated from all other populations of the species (no gene flow)
  9. GE: #4
    Mating is random
  10. GE: #5
    All individuals survive and produce the same number of offspring
  11. Evolution is an opportunistic process.
    Dramatic shifts have a tendency to occur to smaller populations rather than larger ones.
  12. Violation of GE 5
    • Natural selection
    • a. Directional selection: one extreme or other extreme of parabola : environment favored selection
    • b. Stabilizing selection: Middle of parabola. extreme forms become lessened
    • c. Disruptive selection: both sides of parabola: extreme forms favored by environment.
  13. Violation of GE 4
    • Sexual selection; individuals with more attractive traits, better being able to attract mates for off spring generating.
    • ex. peacock tails
  14. Violation of GE 2
    • Genetic Drift: Stochastic fluctuation in allele frequency of a population over time.
    • Stochastic= Random
    • ex. Bottle neck effect: drastic reduction in population size, brought about by SEVERE PRESSURE or a random event.
    • aka. selective pressure
    • some alleles are no longer going to be present.
    • Founder effect- migration of alleles vs. dying off
  15. Violation of GE 3
    gene glow: movement of alleles among population
  16. Pre-zygotic isolation mechanism, how many?
  17. Temporal isolation
    Indv. of diff populations can evolve and reproduce at diff times
  18. mechanical isolation
    instability to reproduce because of physical incapability
  19. behavioral isolation
    ind. of one pop. may not be attracted to an indv. of another pop
  20. ecological isolation
    indv. are in diff places and do not meet
  21. gametic incompatibility
    reproduction cells meet up but do not fertilize
  22. speciation
    process by which idv. diverge into separate liniages and become diff species
  23. hybrid inviability
    hybrid, idv. die before they can reproduce
  24. hybrid sterility
    hybrid ind. unable to produce offspring, unfunctional gametes
  25. sympatric
    no physical separation between populations
  26. avopatric
    physical separation between species