polymorphism and genetics.txt

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polymorphism and genetics.txt
2010-12-10 18:22:57
polymorphism genetics

Lecture 1:polymorphism and genetics
Show Answers:

  1. What factor can change genotype?
  2. What two factors influence phenotype?
    • 1) Genotype
    • 2) Environment
  3. What is a transition point mutation?
    • Purine - Purine
    • Pyrimidine - Pyrimidine
  4. What is a transversion point mutation?
    Purine - pyrimidine (and vice a versa)
  5. What is a missense mutation?
    Point mutation resulting in the change of an amino acid
  6. What is a silent mutation?
    Point mutation that does not change the amino acid
  7. What is a nonsense mutation?
    Point mutation that creates a stop codon (UAA, UAG, UGA)
  8. What is a frameshift mutation?
    When there is a deletion or insertion in a chain that is not a multiple of three.
  9. What is a lethal mutation and what is one example of a lethal mutation?
    • Generally homozygous dominant
    • Cause death before birth or shortly after
    • Tay-Sachs is an example because of the GM2 buildup and neural damage
  10. What is a conditional mutation and what is one form of such a mutation?
    • Is affected by an environmental stimulus.
    • Cancer
  11. What is a loss-of-function mutation and what is an example of such mutation?
    • Generally recessive
    • A complete or partial loss of the function enough so that the phenotype (trait) changes
    • Hemophilia B and Cystic Fibrosis
  12. What is a gain-of-function mutation and what is an example of such mutation?
    • When a protein is reproduced or produced novely
    • Cancer
  13. What is a dominant negative mutation? Example?
    • mutated gene that blocks normal gene activity
    • Occur in multimers
    • Congenital malformations
  14. What is haploinsufficiency? Example?
    • When loss-of-function produces phenotype in hetero- and homo- (50% expression of enzyme)
    • Lack of sufficient enzyme activity
    • Familial hypercholesterolemia
  15. What is an epigenetic change? Example?
    • Not true mutations, alterations in phenotype without true genotype mutation.
    • Cannot be inherited.
    • Generally is a methylation on DNA
  16. What is the main difference between a mutation and a polymorphism?
    • Mutations= infrequent and associated with a disease
    • Polymorphism= DNA variation that is common in population and does not result in a disease
  17. What are the four types of Polymorphisms?
    • SNP
    • STRP
    • VNTR
    • CNV
  18. What is the characteristic of SNP?
    One nucleotide change
  19. What is the characteristic of STRP?
    2-5bp repeats in tandem
  20. What is the characteristic of VNTR?
    14-500 bp repeats in tandem
  21. What is the characteristic of CNV?
    1000s of bp repeats in tandem
  22. What is the one polymorphism that serves as a molecular fingerprint?
  23. Is RFLP better at excluding or recognizing people?
    Excluding people