Mendel

The fruit fly Drosophila melanogaster was first used in 1900 as a useful tool in genetic studies of diploid organisms because it has a short life-cycle, is easily handled and bred, and produces many progeny from a single mating (Mendelian, 2003). It also has a large polytene chromosome in the salivary gland of the third-instar larval stage, which can be used for cytological studies of chromosome aberrations. Many

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ed counts were compared to observed counts using a Chi-Squared test to see if there was a significant difference between observed and expected results. Vials of parental flies were cleared of emerged flies the night before setting up the cross. The next day, early enough to assure virginity of the female flies, the newly emerged flies were sexed and seven or 8 flies chosen of each sex for the parental strain of each cross. Female Drosophila can store sperm from a single insemination for most of her reproductions, and so it is necessary to use virgin females for the parental generation in genetic studies to assure that offspring arise from the cross mating only. Three replicates were done of each cross to assure enough progeny for the next generation. After about two weeks, the progeny of the parental cross had gone through the larval instars and pupal stages and were emerging. Again, seven or 8 flies of each gender were collected for the F1 cross, and three replicates were made. The females did not need to be virgin for this cross because they all carried one wild-type X chromosome and one white-eyed type X chromosome. After another two weeks, the F2 generation emerged, and counts were made on the first day of the eme
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Some common words found in the essay are:
Using Chi-Squared, Independent Assortment, Female Drosophila, Sheets Figures, Y-linked DAZ, Materials Methods, Punnett Squares, Rubin Lewis, Introduction Mendel, Bier Reiter, f2 generation, drosophila melanogaster, white-eyed type, cross wild-type, wild-type female, cross wild-type female, expected results, f2 generation cross, generation cross, generation cross wild-type, day emergence, f1 generation, days emergence, using chi-squared test, female white-eyed male,
Approximate Word count = 2379
Approximate Pages = 10 (250 words per page)

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