| F1: AaBb X AaBb | |||
| ↓ | |||
| F2 ratio | Genotype | Phenotype | Final Phenotypic ratio |
|---|---|---|---|
| 9/16 | A- B- | agouti |
9/16 agouti 4/16 albino 3/16 black |
| 3/16 | A- bb | albino | |
| 3/16 | aa B- | black | |
| 1/16 | aa bb | albino | |
In a cross between agouti (AABB) and albino (aabb),
the F1 are all AaBb and have agouti coat color.
The F2 produced from crossing these double heterozygotes are shown at right.
In the presence of a B allele, black pigment is made.
In the presence of an A allele, the black pigment is deposited on hair in a pattern producing the
agouti phenotype.
In the aa genotype, all of the hair remains black.
In the bb genotype, no black pigment is produced;
this genotype masks or suppresses the expression of the A allele,
and the mouse is black