Unlinked Gene Hypothesis

Abstract: This experiment was meant to look and find gene linkages and determine the crosses of the tan x wild type (black), gray x wild type (black), and tan x gray spores of the Sordaria fimicola. To accomplish the crossing, the plates filled with auger had to be set up with each individual kind of spore. Three plates with two different spore colors of sordaria in each. One plate was black and tan, black and gray, and gray and tan. For gene to centromere distance the standard deviation was 5.6 (tan x wild) and 4.8 (wild x gray). For part two, the linkages for tan and gray was that no linkages appeared due to lack of similarity in numbers with PD and NPD. For wild and tan no crossing occurred 19 times in meiosis I and crossing occurred 38 times in meiosis II. Therefore, at the end of the experiment it was determined that the tan and …show more content…
The first is for the unlinked gene which determines that the unlinked gene hypothesis follows that of Mendel’s Law of Independent assortment. This law states that if the two genes are not linked they should segregate independently at metaphase I of meiosis. So if the gray spore and the tan spore are considered unlinked then the frequency of the PD (parental ditype) and NPD (non-parental ditype) asci along with the segregation independently, should be equal. The second hypothesis is for linked genes and this is that both of the spore coloration are seen on the same pair of homologous chromosomes. This just makes them inherited together due to the linkage physically together. The rule states that Mendel’s law doesn’t correspond with this and it would not make sense if the genes were linked. If the genes were linked then the PD and T asci will show and only a small portion of the NPD would show up. The hypothesis would be that if the gray spore and tan spore genes are linked together, two genes should not segregate independently and the PD frequency should be more than the NPD asci