Genetics 2

  1. Law of segregation
    During meiosis, homologous pairs of chromosomes (and the genes) separate from one another and packed into gametes. At fertilization gametes combine at random to form a new individual
  2. Law of Independent Assortment
    • For 2 genes on a different chromosome, the inheritance of one doesn’t affect inheriting another
    • The genes independently assort , because they are packed into gametes at random
  3. Law Of Dominance
    • When two plants expressing different alleles of the trait are crossed, only one form of the trait is expressed in the F1
    • •The gene that is masked is recessive
    • •The gene that is expressed is dominant
  4. Genotype
    the combonation of allelles that one posesses. (heterozygous, homozygous)
  5. Hemizygous
    only one copy (genes on the X chromosome in males)
  6. Dominant inheritance
    trait is expressed in the hetrozygote (Dd)
  7. Recessive inheritance
    trait is expressed in the homozygote (dd)
  8. Autosomal Inheritance
    Trait expressed on genes on chromosome 1-22
  9. X linked inheritance
    Trait expressed genes on the X (or Y) chromosomes
  10. Penetrance
    Percentage of a persons known to possess a certain mutant gene who actually show the gene
  11. Incomplete or non-penetrance
    A person who has the specific gene and shows no phenotype
  12. Expressitivity refers to
    A genotype is associated with a phenotype of varying intensity
  13. What is incomplete dominance
    • The heterozygous phenotype is intermediate between either homozygote
    • ie pink snapdragon
  14. Co- Dominance
    • Different alleles are both expressed in a heterozygote
    • ie ABO
  15. Where is HLA located?
    Three regions located on short arm of chromosome 6
  16. What HLA class is involved with immune system?
  17. HLA system is important because
    • Important for tissue typing and transplants
    • Disease associations- specific HLA antigens and certain disease such as type 1 diabetes and narcolepsy
    • HLA-DR2 and the HLA-DQB allele are associated with resistance to typ1 DM
  18. BOth the A and B allelles are _____ to O but ______ to eachother
    • dominant
    • codominant
Card Set
Genetics 2