Drosophila Work

Vial1 contains the first filial (F1) generation of the offspring of the parents which were crossed, wild type (+/+) x vestigial (v/v).

Alleles |

v |

v |

+ |

+v |

+v |

+ |

+v |

+v |

Fig1. Shows a monohybrid cross examining a single trait for the F1 generation

Using this monohybrid cross, we are able to predict as best we can, the phenotype of the offspring. Here we see that the wild type phenotype will be present 100% of the time (fig1).

From the results gathered on the day, observations showed that there was only one phenotype present on vial 1 which was wild type (normal wings), and no presence of any other phenotype. Comparing these results to the class total results, we see that there may have been a human error in counting, or students were not able to distinguish between the two phenotypes. The proportion in the class total is approximately 29 wild type: 1 mutant, this means there was probably a small error by a few students which affected the class result.

Comparing my result and the class result to the expected pattern from the monohybrid, I think that the proportion of wild type to the mutant flies in vial 1 is what I expected. That all of the flies in this vial would be heterozygous wild type and there would be no vestigial (recessive trait) phenotypes. This is due to the vestigial (recessive trait) being over masked by the more dominant trait in this cross. All due to the wild type (+/+) carrying homozygous alleles (Brooker et al., 2014).

Vial 2 contains the F2 generation which resulted from crossing the flies from vial 1, wild type (+/v) x wild type (+/v).

Alleles |

+ |

v |

+ |

++ |

+v |

v |

+v |

vv |

Fig 2. Shows a monohybrid cross examining a single trait (Recessive cross).

Alleles |

+ |

c |

+ |...