OSU

BIOLOGY 102 PUNNETT SQUARES
Monohybrid, Dihybrid, and Trihybrid Crosses
Shading in each Punnett Square represents matching phenotypes,
assuming complete dominance and independant assortment of genes,
phenotypic ratios are also presented.

Monohybrid Cross (F1 Generation)
A
A
a
Aa
Aa
a
Aa
Aa
Phenotypic Ratio
 
4
0

Monohybrid Cross (F2 Generation)
A
a
A
AA
Aa
a
Aa
aa
Phenotypic Ratio
 
3
1

Dihybrid Cross (F2 Generation)
AB
Ab
aB
ab
AB
AABB
AABb
AaBB
AaBb
Ab
AABb
AAbb
AaBb
Aabb
aB
AaBB
AaBb
aaBB
aaBb
ab
AaBb
Aabb
aaBb
aabb
Phenotypic Ratio
 
9
3
3
1

Trihybrid Cross (F2 Generation)
ABD
ABd
AbD
Abd
aBD
aBd
abD
abd
ABD
AABBDD
AABBDd
AABbDD
AABbDd
AaBBDD
AaBBDd
AaBbDD
AaBbDd
ABd
AABBDd
AABBdd
AABbDd
AABbdd
AaBBDd
AaBBdd
AaBbDd
AaBbdd
AbD
AABbDD
AABbDd
AAbbDD
AAbbDd
AaBbDD
AaBbDd
AabbDD
AabbDd
Abd
AABbDd
AABbdd
AAbbDd
AAbbdd
AaBbDd
AaBbdd
AabbDd
Aabbdd
aBD
AaBBDD
AaBBDd
AaBbDD
AaBbDd
aaBBDD
aaBBDd
aaBbDD
aaBbDd
aBd
AaBBDd
AaBBdd
AaBbDd
AaBbdd
aaBBDd
aaBBdd
aaBbDd
aaBbdd
abD
AaBbDD
AaBbDd
AabbDD
AabbDd
aaBbDD
aaBbDd
aabbDD
aabbDd
abd
AaBbDd
AaBbdd
AabbDd
Aabbdd
aaBbDd
aaBbdd
aabbDd
aabbdd
Phenotypic Ratio
 
27
9
9
9
3
3
3
1