Card Set Information

2011-04-27 14:35:32

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  1. F1 generation
    first generation - dominant

    [produced purple flowers in Mendel's experiment]
  2. F2 generation (results)
    3:1 ratio of dominant: recessive
  3. Why is F1 dominant, but F2 different?
    because F1 is heterozygous dominant so F2 will vary
  4. phenotype v. genotype
    phenotype: expression of a trait

    genotype: individual's genetic make up
  5. what is complete dominance?
    a diploid individual will have 2 chromosomes

    each chromosome contains a separate gene that codes for that specific trait
  6. does each gene contribute?
    yes, each gene contributes to an allele to genotype-

    but only one phenotype is expressed
  7. kinds of chromosomes in complete dominance?

    where are the genes located?

    located at the same locus
  8. law of segregation
    alleles segregate independently of each other when forming gamete
  9. incomplete dominance
    heterozygote exhibits a phenotype that is intermediate between he homozygous counterparts

    [same capital letter, different superscript]
  10. codominant
    heterozygote exhibits both phenotypes
  11. what allele is codominant?
    blood type
  12. Law of Independent Assortment
    genes on different chromosomes assort independently of each other
  13. what kind of genes assort independently? (in other words, what genes are on different chromosomes)
    genes that code for different traits:

    i.e. pea shape and pea color
  14. phenotypic ratio of a dihybrid cross
  15. II. Humans - which chromosome establishes sex of the individual?
    23rd chromosome
  16. male v. female
    male = X and Y

    female = X and X
  17. what does sex-linked mean?
    when a gene is found on the sex chromosome -

    will sort dependently on the sex of the individual
  18. which male chromosome carries the allele for sex-linked traits?
    X not Y
  19. if a dominant allele is carried by X chromosome in the male is it expressed? what about if it's recessive?
    always expressed: dominant or recessive
  20. III. Evolution - what is a gene pool?
    total of all alleles in a population
  21. the course of development (zygote to adult) reflects....
    evolutionary history

    [human fetus has pouches reflecting a gilled ancestor]
  22. taxonomic classification
    Kingdom, Phylum, Class, Order, Family, Genus, Species
  23. what determines a species?
    all organisms that can reproduce fertile offspring
  24. natural selection
    whoever produces more offspring

    [doesn't matter what you do, all that matters is that the species doesn't go extinct]
  25. survival of the fittest
    one species will exploit the environment more efficiently

    leads to extinction of the others with the same niche
  26. r-selection
    involves producing large numbers of offspring that mature rapidly

    (little or no parental care)
  27. k-selection
    slow maturing of offspring

    (strong parental care)
  28. growth curves for r- and k-selection
    r-selection = exponential

    k-selection = sigmoidal
  29. who has high mortality rate? who can survive in changing environments?
  30. what is polymorphism?
    some phenotypes vary gradually within a species [ex: height]
  31. what is symbiosis?
    relationship between two species
  32. mutualism
    beneficial for both
  33. commensalism
    beneficial for one, doesn't affect the other
  34. parasitism
    beneficial for one, detrimental for the other
  35. genetic drift
    one allele may be permanently lost due to the death of all members having that allele
  36. binomial theory: what does it predict?
    genotype frequency of a gene in a population in Hardy-Weinberg equilibrium
  37. what are the equations?
    p2 + 2pq + q2

    p + q = 1
  38. What are chordates characterized by?
    bilateral symmetry

    (not all of them have a backbone)
  39. or chordates proteostomes or deuterostomes?
    deuterostomes -

    anus develops from or near blastopore
  40. What other features do chordates have?
    • coelom
    • notochord
    • paryngeal slits
    • dorsal, hollow nerve chord
    • tail
  41. what is a notochord?
    axial support, not the backbone
  42. verbrata
    have notochord replaced by cartilage or bone structure

    also have a distinct brain enclosed in skull