1. Law of independent assortment

2. Mendel’s Laws Law of Independent Assortment
Alleles sort independently of one another
Alleles on one chromosome don’t control the inheritance of alleles on another chromosome
Mendel made this conclusion after performing dihybrid crosses
Crosses with two traits

3. Dihybrid Crosses
A - green seeds, a – yellow seeds B – purple flowers, b – white flowers AaBb x Aabb AB Ab aB ab

4. Dihybrid Crosses AB Ab aB ab
AABb
AAbb
AaBb
Aabb
aaBb
aabb

5. Dihybrid Crosses Phenotypic Ratio - 6 green seeds, purple flowers
6 green seeds, white flowers
2 yellow seeds, purple flowers
2 yellow seeds, white flowers

6. Sample Problems
In peas, tall plants are dominant to dwarf plants and round seeds are dominant to wrinkled. A heterozygous tall, round seed plant self-fertilizes. What would the genotypic and phenotypic ratios be?