Bio Chapter 14

  1. true-breeding
    flower produce same color byself-pollination in successive generations 
  2. hybridization
    mating, or crossing, of two true-breeding varieties
  3. P generation (parental generation)
    true-breeding parents
  4. F1 generation (first filial generation)
    hybrid offspring
  5. F2 generation ((second filial generation)
    F1hybrids to self-pollinate (or to cross-pollinate with other F1 hybrids)
  6. Mendel experiment
    • F1 all purple but F2 3:1 ration of white -> concludes that purple is not destroyed but its dominant and white is recessive
    • Conclusion:
    • -alternative versions of genes account for variations in inherited characters
    • -for each character, an organism inherits two copies of a gene, one from each parent
    • -one is dominant allele,  the other, the recessive allele
    • -law of segregation - two alleles seperate into different gamate
  7. Locus & alleles
    • locus: a spot on chromosome that hold the characters of the traits
    • allele: in locus that hold the trait of that character
  8. homozygous
    • has a pair of identical alleles for a character Ex: PP or pp 
    • - true breeding
  9. heterozygous
    • different alleles Ex: Pp
    • not true breed cuz it produde 3:1 (white and purple)
  10. phenotype & genotype
    • phenotype : traits( colors) 1st allele
    • genotype : genetic makeup (PP, Pp), 2nd allele
  11. testcross
    Breeding an organism of unknown genotype so it can revealthe genotype of that organism
  12. monohybrid cross.
    • cross between such heterozygotes
    • dihybrids: (YyRr) 2 traits
  13. law of independent assortment
    • Mendel’s dihybrid experiments
    • each pair of alleles segregates independently of each other pair of allelesduring gamete formation. Ex: color doesnt affect shape
    • -dependent (3:1) , independent (9:3:3:1)
  14. Punnete sqaure
    • Rr&Rr = 1/2 Rr, 1/4 RR, 1/4 rr
    • Rr&RR = 1/2 Rr, 1/2 RR

    find all possible possibilities then add up the products
  15. codominance
    • two alleleseach affect the phenotype in separate
    • dominant has enzyme synthesize adequate amounts of branched starch
  16. Tay-Sachs disease
    • inherit two copies of the Tay-Sachs allele(homozygotes)
    • qualifies as recessive
    • heterozygote condition does not lead to diseasesymptoms
  17. pleiotropy
    Most genes, however,have multiple phenotypic effects
  18. epistasis
    phenotypic expression of a gene at one locus alters that of a geneat a second locus
  19. quantitative characters
    • characters vary in the population in gradations along a continuum
    • indicates polygenic inheritance, an additive effect of two or more genes on a single phenotypic character
    • AABccc = AaBbCc
  20. norm of reaction
    • arange of phenotypic possibilities due to environmental influences.
    • multifactorial - many factors, both geneticand environmental, collectively influence phenotype
  21. cystic fibrosis,
    • European descent, one out of 25 (4%) carries
    • chloride transport channels are defective or absent inthe plasma membranes
Card Set
Bio Chapter 14
Mendel and Gene Idea