BIOL 111 Lecture Notes - Lecture 25: Thomas Hunt Morgan, Mendelian Inheritance, Wild Type
Document Summary
Chapter 15 the chromosomal basis of inheritance (pt. 1): Mendelian inheritance has its physical basis in the behavior of chromosomes. Several researchers proposed in the early 1900s that genes are located on chromosomes. The (cid:271)eha(cid:448)ior of (cid:272)hro(cid:373)oso(cid:373)es duri(cid:374)g (cid:373)eiosis (cid:449)as said to a(cid:272)(cid:272)ou(cid:374)t for me(cid:374)del"s la(cid:449)s of segregation and independent assortment. Mendelian genes have specific loci on chromosomes. Pro(cid:448)ided (cid:272)o(cid:374)(cid:448)i(cid:374)(cid:272)i(cid:374)g e(cid:448)ide(cid:374)(cid:272)e that (cid:272)hro(cid:373)oso(cid:373)es are the lo(cid:272)atio(cid:374) of me(cid:374)del"s herita(cid:271)le factors. Morgan worked with fruit flies: because they breed at a high rate, a new generation can be bred every two weeks, they have only four pairs of chromosomes. Morgan first observed and noted: wild type, or normal, phenotypes that were common in the fly populations. Traits alternative to the wild type: are called mutant phenotypes. Correlati(cid:374)g beha(cid:448)ior of a ge(cid:374)e"s alleles (cid:449)ith beha(cid:448)ior of a chro(cid:373)oso(cid:373)e pair. Morgan determined: that the white-eye mutant allele must be located on the x chromosome.
