Punnett Sqaures and Dihybrid crosses
Cross a heterozygous red cheetah with a heterozygous red cheetah.
D (dominant) = Red
Note: heterozygous is always the dominant trait.
R (recessive) = ? (pink)
Note: When the problem doesn't tell you the recessive trait, you can put anything you want.
Ph (phenotype) = color
Note: The phenotype is the outward appearance or physical trait.
G (genotype) = Aa x Aa
Note: Genotype is the gene pair. (Ex: Bb x Bb)
Genotype Phenotype
AA= 1/4 Red = 3/4 (75%)
Aa= 2/4 Pink= 1/4 (25%)
aa= 1/4
D (dominant) = Red
Note: heterozygous is always the dominant trait.
R (recessive) = ? (pink)
Note: When the problem doesn't tell you the recessive trait, you can put anything you want.
Ph (phenotype) = color
Note: The phenotype is the outward appearance or physical trait.
G (genotype) = Aa x Aa
Note: Genotype is the gene pair. (Ex: Bb x Bb)
Genotype Phenotype
AA= 1/4 Red = 3/4 (75%)
Aa= 2/4 Pink= 1/4 (25%)
aa= 1/4
Cross a white, skinny pig with a heterozygous pink, heterozygous fat pig.
D = pink, fat
R= skinny, white
Ph#1= color Genotype
Ph#2= size RpFf = 4/16
G#1= Rr x Ff Ppff = 4/16
G#2= rr x ff rrFf = 4/16
Possible Sets rrff = 4/16
RF RF Phenotype
Rf Rf Pink, fat = 4/16
rF rF Pink, skinny = 4/16
rf rf White, fat = 4/16
White, skinny = 4/16
D = pink, fat
R= skinny, white
Ph#1= color Genotype
Ph#2= size RpFf = 4/16
G#1= Rr x Ff Ppff = 4/16
G#2= rr x ff rrFf = 4/16
Possible Sets rrff = 4/16
RF RF Phenotype
Rf Rf Pink, fat = 4/16
rF rF Pink, skinny = 4/16
rf rf White, fat = 4/16
White, skinny = 4/16