11.2 - Dihybrid Inheritance

Definition of Dihybrid Cross

Dihybrid inheritance involves the inheritance of two characteristics where each characteristic is controlled by a different gene. The dihybrid inheritance experiment on pea plants involves the colour and shape of the seeds.

Gametes: BK, Bk, bK and Bk

Ratio of F2 phenotype

9 round, yellow seed : 3 round, green seed : 3 constricted, yellow seed : 1 constricted, green seed

Figure 6 - Dihybrid inheritance for the shape and colour of pea plants seeds.

Mendel's Second Law

Mendel's Second Law , also called Law of Independent Assortment states that each allele from a pair of alleles can combine randomly with any allele from another pair during the formation gametes.

• Summary from Mendel dihybrid experiment
  • A new combination emerges in F2 generation, that is constricted, yellow seeds and round, green seeds.
  • Two characteristics are combined in F1 but are separated and react freely in F2 generation.