Backcross

This article was checked by pedagogue
This article was checked by pedagogue

This article was checked by pedagogue, but more than year ago.

Signature:  Prof. Ondřej Šeda, M.D., Ph.D. (talk)

Backcross (Bc) refers to mating of heterozygous F1 generation individual with the homozygous parental generation individual. In the presence of complete dominance (A > a), the following genotypic and phenotypic ratios can be found in the Bc generation:

Monohybridism (single locus / gene, two alleles)

Bc – Monohybridism:

  • Aa x AA

Genotype ratio: 1 (AA) : 1 (Aa)

Phenotype ratio: uniform



  • Aa x aa

Genotype ratio: 1 (Aa) : 1 (aa)

Phenotype ratio: 1 (Aa) : 1 (aa)


Dihybridism (two loci / genes with two alleles each)

Bc – Dihybridism:

  • AaBb x AABB

Genotype ratio': 1 (AABB) : 1 (AABb) : 1 (AaBB) : 1 (AaBb)

Phenotype ratio: uniform



  • AaBb x aabb

Genotype ratio: 1 (AaBb) : 1 (Aabb) : 1 (aaBb) : 1 (aabb)

Phenotype ratio: 1 : 1 : 1 : 1



Homozygote

Heterozygote