Biology 1201A Lecture Notes - Lecture 1: Antennapedia, Wild Type, Zygosity
Document Summary
Drosophila melanogaster, the fruit fly, is a common study organism in genetics. Its short life, small size, large number of offspring, and many easily observable phenotypic variations make it ideal to investigate patterns in inheritance. In addition, it only has four different chromosomes: three pairs of autosomes, and one pair of sex chromosomes. Female drosophila are xx and males are xy. Drosophila are diploid, so the standard vocabulary of homozygote and heterozygote is applicable. Likewise, we can apply the standard recessive versus dominant alleles vocabulary. Despite these similarities with what we have learned thus far in the course, drosophila genetic notation is quite different from the standard a/a notation we typically use. Drosophila of typical appearance are said to have (cid:858)wild-type(cid:859) phenotypes for genetically- controlled traits (e. g. body colour, eye colour, wing shape, etc). Mutations that exist naturally or are created in laboratories produce flies with different phenotypes from the wild-type.