Punnett Analysis


Reginald C. Punnett devised a method for analysis of genetics crosses,
involving construction of a square:

  • For a monohybrid
    parent1
    phenotype
    parent2
    phenotype
    parent1
    genotype
    X parent2
    genotype
    gamete1 gamete2
    gamete1 zygote1 zygote2
    gamete2 zygote3 zygote4
    offspring
    genotype count phenotype prob
    . . . .
    . . . .
    . . . .

  • Enter parental descriptions and gametes
  • . . parent 1 as rows
    hybrid
    Aa X
    gamete1 gamete2
    A A A
    a a a
    offspring
    genotype count phenotype prob
    . . . .
    . . . .
    . . . .

  • Enter parental descriptions and gametes
  • . . parent 1 as rows, parent 2 as columns
    hybrid hybrid
    Aa X Aa
    A a
    A A A A a
    a A a a a
    offspring
    genotype count phenotype prob
    . . . .
    . . . .
    . . . .

  • tabulate zygotes
  • and calculate percents
    hybrid hybrid
    Aa X Aa
    A a
    A A A A a
    a A a a a
    offspring
    genotype count phenotype prob
    AA 1 type A 25%
    Aa 2 hybrid 50%
    aa 1 type a 25%

  • or.. with dominance
    offspring
    genotype count phenotype prob
    AA 3 dominant 75%
    Aa
    aa 1 recessive 25%

    For a dihybrid, click
    NEXT



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    © 2004 Prof. LaFrance, Ancilla College