Biology 2

  1. Taxonomy
    classification of organisms into groups
  2. What are the characteristics of mammalia?
    mammory glands and hair
  3. Evolution
    change in gene/allele frequency overtime within a population
  4. DNA
    code for how to synthesize a protein
  5. Chromosome
    one big long strand of DNA
  6. Homologous
    23 chromosomes that are identical
  7. Genes
    section of DNA codes for a specific protein
  8. Alleles
    alternate version of DNA
  9. Dominant
    a gene that is always expressed
  10. Recessive
    a gene only expressed if NO dominant is present
  11. Artificial Selection
    selecting and breeding individuals that posses desired traits, the human does the selecting.
  12. Comparative Anatomy
    anatomical similarities between many species gives signs of common descent
  13. Homology
    similarity in characteristics that results from common ancestry
  14. Homologous Structures
    anatomical similarities in different organisms
  15. Vestigal Organs
    structures of marginal or no importance to the organism
  16. Genotype
    combination of alleles
  17. Phenotype
    how that combination of alleles are expressed
  18. Evolution by natural selection
    • 1. there is much variation in a population
    • 2. much of this variation is heritable
    • 3. most organisms produce more offspring than
    • survive to reproduce
    • 4. the individuals that survive are the ones that are
    • best fit for that environment
    • 5. the environment is constantly changing
  19. Population
    group of individuals of the same species living in the same place at the same time
  20. Gene Pool
    total collection of genes in a population at any one time
  21. Microevolution
    relative frequencies of alleles in a population change over a number of generations causing a change in gene pool
  22. 3 random components of sexual reproduction
    • independent orientation of homologous chromosomes
    • fertilization
    • crossing over
  23. What is the ultimate source of genetic variation?
  24. What is the source of most genetic variation in a population that reproduces sexually?
    unique combination of alleles
  25. 3 main causes of evolutionary change
    • natural selection
    • genetic drift
    • gene flow
  26. Gene flow
    transfer of alleles from one population to another as a result of the movement of individuals
  27. Adaptive evolution
    evolution that results in a better fit between organisms and their environment
  28. Sexual Dimorphism
    difference in appearence
  29. Balancing selection
    natural selection maintains stable frequencies of 2 or more phenotypic forms in a population
  30. Frequency dependent selection
    maintains 2 different phenotypic forms in a population
  31. Selection pressure
    whatever is selecting for and against individuals
  32. Evolutionary fitness
    ability to survive and reproduce
  33. How do you measure fitness?
    by the production of fertile offspring
  34. 3 key points to natural selection
    • population event
    • acts on heritable traits
    • not goal directed
  35. Where does genetic variability come from?
    • ultimate- mutation
    • proximal- sexual reproduction
  36. Environmental selection pressures
    • stressful environment
    • predation
    • competition
  37. Morphology
    means appearence
  38. Non-selection influences
    • gene flow
    • genetic drift
  39. Genetic drift
    change in gene/allele frequency of a small population simply by chance
  40. Example of genetic drift
    • bottleneck effect
    • founder effect
Card Set
Biology 2
Evolution and Genetics