BSC 114 Lecture Notes - Lecture 22: Polyploid, Mitochondrion, Organelle
24 Mar 2016
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Document Summary
Mendelian inheritance has its physical basis in the behavior of chromosomes. Mitosis and meiosis were first described in the late 1800s. In the early 1900s, several researchers proposed that genes are located on chromosomes because the behavior of chromosomes during meiosis could account for mendel"s laws of segregation and independent assortment the chromosome theory of inheritance. Mendelian genes have specific loci (positions) in chromosomes. The first solid evidence associating a specific gene with a specific chromosome came from research conducted by the embryologist thomas hunt morgan. Morgan"s experiments with the fruit fly, drosophila melanogaster, provided convincing evidence that chromosomes are the location of mendel"s heritable factors. Several characteristics make fruit flies a convenient organism for genetic studies: > a new generation can be bred every two weeks. Females have two x chromosomes (xx) and males have 1. Morgan noted wild type (normal) phenotypes that were common in the fly populations. Traits alternative to the wild type are called mutant phenotypes.
