Inle Klsiinmk Essay, Research Paper

Since the first single basepair substitution undergoing an inherited disease inhumans, 20 years have elapsed. The disease in humans was charcterized at the DNA level. The initiative was recently taken to be established for resources for pathological geneticvariants.Spontaneously mutations may occur or they maybe induced irradiation, someexternal stimulous.Gene mutation in humans is a highly specific process with important implicationsfor the nature prevalance and diagnosis of genetic disease.The recognition of certain DNA sequences are hypermutable and has yielded duesto the endogenous mutational mechanisms that are involved and provided into theintricacies of DNA replication and repair.A fuller understanding of mutational processes maybe important in moleculardiagnostic medicine by improvements in design efficancy of the search of mutations procedures and strategies in genetic disorders. Fruit fly Drosophila, is what research in genetics came to focus on. from egg tomaturity this was an animal with a generation time of 14 days and capable of producing1000 eggs in their life time. They were also very inexpensive, small, and easy to maintainand breed. When this research started (the new era in genetic research.) Thomas HuntMorgan had one Major disadvantage in 1909, there were only one type to work with, the(wild type). With in a year and thousands of flies, Morgan found his first mutant. Thisone had white eyes instead of red-colored eyes. By 1915 him and his students had found85 different mutants. By: Tashia MaderFootnotes: Figure 10-11 From: ( T.H. Morgan, The Theoryof Genes, ) pg. 435 Cell BiologyEleven pairs of chromosomes were found by Sutton in grasshoppersspermatogonia. In 1901 the accessory chromosomes were involved with determination of

sex of the individual. A few years later this waas confirmed and it was shown that the mlecould be distinqueshed by it s chromosomes from the female. Females gametes will havean X chromosome, and half of the sperm will have X and half will have Y chromosomes.Association of genes into linkage groups was found to occur, ussually the linkagewas incomplete, new cobinations of characteristics were found. The frequency with theunexpected combinations will occur, being varied depending on two genes that arecompared, but will be constant for any pair. Two genes that are located on the Xchromosome, will typically have approximate 1% new combinations.Morgan offered an explantion for the breakdown in linkage and for the variation init s strength in 1911. Morgan capitalized on his observation and proposal, he suggestedthat the phenomenon (crossing over), this could account fot new combinations among theoffspring.Exchange of chromosomal parts occur durring meiosis, then potential exsistancefor genes that have previously has been present on the same chromosome and becomeseparated from each other and occupy positions on different chromosomes. By: Tashia MaderFootnote- Phenomenon: An occurance or fact that is directlyperceptible by the senses.Offspring with chromosomes with one characteristic located on the maternal partof a chromosome with another characteristic on a paternal part of the same chromosome.With strong evidence the percentages of recombinations were constant for a pairof genes that are positioned along the chromosome which was fixed reguardless of the cellin an individual in the population.Mutation- A change in the hereditary material of anorganism, producing a change in some characteristics of theorganism; especially, alternation of the character of a GENE. jklhjdkasufakjk