Albino Genetics slide presentation

No Genetics Calculator? Follow the directions below!

D+SZ X D+SZ

Clown
black X Clown black

First Allele | Second Allele | Genotype | Phenotype |

25% SS | 6.25% DDSS | Black (DD) blushing | |

25% DD | 50% SZ | 12.5% DDSZ | Black (DD) clown black |

25% ZZ | 6.25% DDZZ | Black (DD) zebra | |

25% SS | 12.5% D+SS | Turquoise | |

50% D+ | 50% SZ | 25% D+SZ | Clown black |

25% ZZ | 12.5% D+ZZ | Zebra lace | |

25% SS | 6.25% ++SS | Blushing | |

25% ++ | 50% SZ | 12.5% ++SZ | Silver Clown |

25% ZZ | 6.25% ++ZZ | Zebra | |

This is the way I figure out
crosses. The first step is to
figure how many alleles you are working with.
In this cross there are just 2. If
we added a 3^{rd} allele like
smokey there would be a third column after the zebra stripeless column.

Step 1 is to take the first
allele, in this case Dark and figure out the genotypes of just that cross.
In this case there were 3 possibilities.
This is just simple 2 by 2 Punnett square. 25% DD, 50% D+, 25% ++

D | + | |

D | DD | D+ |

+ | D+ | ++ |

Leave some room between
these 3 outcomes, as each one will get all of the results from the next allele
SZ X SZ

S | Z | |

S | SS | SZ |

Z | SZ | ZZ |

25% SS, 50% SZ, 25% ZZ

Each of these 3
possibilities is added to each of the 3 genotypes from the first allele.
So we end up with 9 resulting genotypes.
If this second allele had 4 possibilities you would end up with 12 total.

Total percentages are just
multiplications of each one. 25% of
25% is 6.25% etc.

If there was a third allele
it would be added as multiple entries after each of the second alleles.
You could end up with a maximum of 64 different genotypes from 3 alleles.
In reality I can’t think of any other genes that share the same locus
besides the dark and stripeless locus. So
max would be 48

Hope this helps.