Intro Microbiology

1 Gabriel Tillet To the Bitter End: A Case n the Genetics of PTC Sensitivity Part 1: Discovery 1. L.H. Snyder uses the term “Mendelian marker” to state that any Mendelian trait that is inherited may be used as a marker for future experiments. 2. The questions that Dr. Snyder will address are: “If PTC is inherited, could it be used as a Mendelian marker?” Another question he can come up with is: “Is PTC inherited? Does the ability to inherit this trait make it a Mendelian Marker?” 3. His hypothesis is, If PTC taste sensitivity is inherited, would it be safe to call/ use it as a Mendelian marker. Part 2: Mendelian Genetics 1. The evidence that indicates that the ability to taste PTC is inherited is taken from the Table provided. By observing the table you see that for both sets of parents that either of them can taste or only one can taste, the number of children who could taste is higher than the number of children who can not taste. The one where neither parent can taste supports this idea because no children come out as tasters. 2. It is important for Dr. Snyder to verify the number of males and females having similar proportions of tasters and non-tasters phenotype. Because if gender affects PTC sensitivity, the amount of tasters and non-tasters in both groups were represented equally to avoid errors. 3. Couples who can taste PTC have children who cannot taste PTC because; the parent’s posse’s alleles which are both heterozygous dominant. 2 4. The significance of couples who cannot taste PTC never have children that can, signifies that PTC sensitivity is a dominant trait that must be carried by at least one parent to be passed down to their children. 5. Based on the data, I can could conclude that PTC taste blindness is a homozygous recessive trait. The evidence I have to support this is that children who have both parents that cannot taste PTC are not able to pass down the gene to their offspring. Proving that their children will also be PTC taste blind. 6. The ratios that are expected from testcrosses are 0:4:0 and 0:2:2. The ratio 0:4:0 represents when a homozygous dominant and a homozygous recessive are crossed. The ratio shows that the children will only be able to have the heterozygous dominant genotype. The 0:2:2 ration represents when a heterozygous dominant and a homozygous recessive are crossed. The ratio shows that no children will come out homozygous dominant, but there is a 50-50 chance that the children will either come out homozygous recessive or heterozygous dominant. Part 3: Molecular Genetics 1. A gene family is a set of genes that function as a result of several duplications. 2. A SNP is a single nucleotide polymorphism, which is when there are single base pair differences in a DNA sequence between members of a species; they are the alleles that produce phenotypic differences. A halotype is a set of alleles on a single chromosome or on a part of the chromosome. SNP halotypes can be determined by using tag-SNPs that are specific to identifying halotypes. 3. Assuming PAV allele is the original one, then the AVI is a missense codon. A missense codon is when there is a change to the sense codon, resulting in another sense codon that

All courses in MCB

Popular Documents