Genetics 4

  1. allelic series
    order of dominance based on activity of alleles protein product.

    Alleles can be completely dominant or recessive.

    or can display forms of  incomplete dominance or co-dominance.
  2. biosynthetic pathway
    Network of interacting genes, produce molecule or compound as end product.
  3. haplosufficient
    one haplo copy is enough to express wild type phenotype.
  4. haploinsufficient
    one copy is not enough to produce wild type phenotype.
  5. loss of function mutation
    decrease or complete loss of gene activity

    usually recessive
  6. gain of function mutation
    alleles that have acquired a new function or are altered to express more activity than wild type allele.
  7. null mutation
    complete loos of gene function

    aka amorphic mutaion
  8. leaky mutation
    partial loss of gene function aka hypomorphic mutation
  9. dominant negative mutation
    multimeric proteins composed of two or more polypeptides join together to form a functional protein.  May suffer complete of partial loss
  10. neomorphic mutation
    • new gene activities not found in wild type
    • usually dominant
  11. codominance
    progeny has heterozygous phenotype different from each homozygous parent.
  12. lethal mutations
    single gene mutations that cause death usually inherited as recessive   mutants, recessive alles that only kill homozygotes
  13. sex limited traits
    sex has influences gene expression.May limitate expression on one sex but not the other.  both sexes carry the genes for sex limited traits bt genes are expressed in only one sex.
  14. sex influenced traits
    phenotype corresponding to particular genotype differs depending on sex
  15. delayed age of onset
    some dominant lethal alles sidestep natural selection by not showing abnormalities till after they have a chance to reproduce.
  16. penetrance
    phenotype consistent with genotype
  17. nonpenetrant
    certain genotype fails to produce corresponding phenotype.
  18. incomplete penentrance
    traits for which nonpenentrant individuals  occassionaly iccur
  19. variable expressivity
    same genotyphe producess phenotypes that vary in the degree of expression of the allele of interest.
  20. gene  environmental interactions
    resulf of the influence of environmental factors (NON GENETIC FACTOR)
  21. pleiotropy
    alteration of multilple distinct traits of an organism by mutating a single gene
  22. gene interaction
    collaboration of multiple genes in producing a single phenotype
  23. biosynthetic pathway
    network of interacting genes  produce a molecule of compound as final product
  24. one gene one enzyme hypothesis
    each gene produces an enzyme, each enzyme has a specific role that produces a phenotype.
  25. genetic dissection
    test the ability of a mutant to execute each step of biosynthetic pathway , assembles steps in a pathway by  determining the point in which the pathway is blocked in each mutant.
  26. epistasis
    gene interactions
  27. epistatic interactions
    an allele of one gene modifies or prevents the expression of alleles at another gene
  28. complementary gene interaction
    requires genes to work in agreement to produce a single gene product
  29. genetic complementation
    ability of two mutants with same mutant phenotype to produce progeny with wild type phenotype.  More than one gene is involved in determining phenotype.
  30. duplicate gene action 15:1
    either encode same gene product, or encode gene products  that have same effect in a single pathway or compensatory pathways.
  31. dominant gene interaction
    9:6:1 ratio of phenotypes of progeny in a dihybrid cross
  32. recessive epistasis
    homozygosity for a recessive allele at one locus can mask the phenotypic expression of a second gene.
  33. dominant epistasis
    dominant allele at one locus masks the expressio of alleles at a second locus
  34. dominant suppression
    similar to dominant epistasis, but occurs when a dominant allele of one gene completely suppresses the phenotypic expression of alleles of another gene.
  35. genetic heterogeneity
    mutations of different genes can produce the same, similar, or abnormal phenotypes.
  36. genetic complementation
    mating of two organisms with same or similar abnormal phenotype can have offspring with wild type phenotype.
  37. complementaion group
    mutations that fail to complement one another consist of one or more mutant alleles of a single gene.

    consist of mutants whose phenotypes fail to complement one another, and complement mutants in other complementation groups.
Card Set
Genetics 4
chapter 4