Mendelian Cracker

Introduction - Background - PTC stands for Phenylthiocarbamide, a chemical that can either taste very bitter, or nothing at all depending on the genetic makeup of the subject. People who can taste this are supertasters. Supertasters are people who are more sensitive to taste than others, this is linked to the tas2r38 gene. Another link to supertasting is fungiform papillae density. Fungiform papillae are club shaped parts on the tongue that a slightly raised over the rest of the tongue; they have taste buds that can distinguish between the five tastes sweet, sour, bitter, salty, and umami.

This lab included determining our PTC (a chemical substance causing bitter tastes) phenotype and genotypes through taste-tests and DNA-analysis. After performing my taste-test, I was unable to taste the bitterness of the PTC, so I concluded that no movement would take place in the gel electrophoresis wells.

The foundation of genetics lies with the principles that Gregor Mendel outlined after his experiments with pea plants where he discovered the relationship between physical characteristics, or phenotype, and genetic traits, or genotype. This experiment aimed to reproduce Mendel’s results with the Brassica rapa plant, noted for it’s fast generation time, and anthocyanin, a purple pigment that can be visually tracked through subsequent generations. It is important for experiments resulting in scientific discovery to be replicable and peer reviewed. Since Mendelian genetics are the foundation of scientific education, including answering questions about

The X2 value for each cross was calculated to determine that the observed and expected ratios according to Mendelian inheritance were close in agreement (Garey et. al 2013). In order to determine if the observed deviations for each cross were within the limits expected by chance,10% and 25% of similar trials. The monohybrid autosomal ap/ap x +/+ cross results were the most similar in comparison of results and probability of all the crosses. The chi-square results were extremely similar as expected and both accept the hypothesis that deviations

Introduction: Genetics is the study of how genes and heredity combine to create traits in living organisms. Gregor Mendel disproved the theory that heredity comes only from parents. He discovered that there were dominant and recessive genes and his “Law of Dominance” has been used to selectively breed plants and animals for particular attributes. It has also been successfully adopted to identify the risk of passing down genetic diseases. Francis Galton took Mendel’s discoveries further by studying multifactoral inheritance and discovering ‘blending traits’, also known as continuous variation. With these traits, involvement of a wide range of genetic and environmental factors results in the creation of wide-ranging genotypes.

Purpose: The purpose of the genetic inheritance experiment is to show the understanding of how the reception of genetic qualities by transmission from parent to offspring work. Procedures: For the first exercise, I recorded the F2 seeding color. I recorded the frequency of green: white plants that will result in the F2 progeny.

Humans show extensive variations in taste sensitivity, which explains why each enjoy different types of food (Kim and Drayna 275). This fact is due to genetic origin and has opened a new door to determine the ability to taste Phenylthiocarbamide (PTC). This substance has an unusual capability of being tasteless or bitter depending on the genetic makeup of individuals. The discovery of this phenomenon was in 1931 by a chemist called Arthur Fox, who conducted an experiment among family and friends and noticed that some people tasted nothing while others tasted it bitter. After, the discovery many investigations were conducted to see the connections between Mendel’s principles of inheritance and the ability to taste PTC. Studies indicated that the ability to taste PTC in inherited as a Mendelian dominant (T), leading to the finding of a gene known as TAS2R38, which codes for a receptor protein that binds PTC (Overath, 2011).

You can either be a homozygote which is when you have two copies of the same gene or you can heterozygote which is when you have one copy of each gene

Genes come in different varieties, called alleles. Somatic cells contain two alleles for every gene, with one allele provided by each parent of an organism. Genotype refers to the information contained in an organisms DNA, or genetic material. Its phenotype is the physical

Specifically, a humans’ ability to detect Phenylthiocarbamide (PTC). Humans typically fall into two groups; Tasters vs Non-tasters. The ability to discern the bitter taste that PTC provides. Scientists have discovered that the key to this ability resides on the 7th chromosome in a gene called TAS2R38. PTC is a synthetic compound that is found in natural substances such as cruciferous vegetables. Possible reasons for the natural selection of the tasting mutation could be for detecting poisons in plants and to prevent high quantities of PTC in the body, which can interfere with iodine metabolism. The distribution of this gene varies globally, the highest percent of non-tasters being the aborigine of Australia at 49.7%, the lowest percent of non-tasters being the residents of central America at 9.9%. Even in our primate cousins have a similar mutation that evolved separately.

For example, FF (Homozygous Dominant) and Ff (Heterozygous Dominant). A phenotype is your physical appearance (product of the genes). For example, if B is the coding for brown eyes, and your genotype is BB (Homozygous Dominant), you will have brown eyes.

Gregor Mendel, known as the father of genetics researched about genetics before which there was a common belief that a child may inherit certain physical characteristics or traits or there are physical similarities among the family members such as the parents with grey eyes will have children with grey eyes or if there is baldness in the family history then the same pattern may follow in the further generations as well. But, later after Mendel researched about it people got to know about specific mechanisms due to which such transfer of traits takes place from parents to the child.

Many concepts relevant to this topic are discussed in the article titled, “Decline in Taste and Odor Discrimination Abilities with Age, and Relationship between Gustation and

Gene- a piece of DNA that will carry the information it needs to make a specific protein.

Beginning in 1856 with Mendel's work on heredity, it tells the story of man’s struggle to decipher the human genome, understand it, and use it for both good and evil. The Gene: An Intimate History also tells the personal story of the Mukherjee family and their