Drosophila Lab Report

In this experiment we tested to see what the offspring of an unknown cross of an F1 generation would produce. After observing the F2 generation and recording the data we found some of the Drosophila showed mutations, two in particular. The mutations were the apterus wings, and sepia eyes. After collecting our data through observation, a Chi-test was conducted resulting in a Chi-value of 5.1 and a p-value of .2. Since the p-value was greater than 0.05, there was no significant change in the data. This proved that the Drosophila flies still followed the Mendelian genetics of a 9:3:3:1 ratio.

Butterflies have many genes which are expressed into ways that are either dominant, or recessive. For example to have blue eyes the dominant allele would be (B) and the recessive allele would be (b).

4. Clear wing, Black eye, and Hairless (c, b, and h) are linked, recessive traits carried on

The parents are both homozygous. The homozygous dominant would represent the wild type. And the homozygous recessive would represent the other fly parent of a different strain. The F1 generation would consist of 100% Wild Type but they would all be heterozygous in carrying the recessive gene.

Introduction: The intention of this lab was to gain a better understanding of Mendelian genetics and inheritance patterns of the drosophila fruit fly. This was tasked through inspecting phenotypes present in the dihybrid crosses performed on the flies. An experimental virtual fly lab assignment was also used to analyze the inheritance patterns. Specifically, the purpose of our drosophila crosses is to establish which phenotypes are dominant/recessive, if the traits are inherited through autosome or sex chromosomes and whether independent assortment or linkage is responsible for the expressed traits.

melanogaster, leaving B and D to be our mutants. Before crossing our populations, we made not of each one’s phenotype in order to see how crossing them would affect their phenotypes: Population B flies had no wings and red eyes, population D had full wings and black eyes and population G had full wings and red eyes. We expected the resulting phenotypes to be some sort of combination, revealing which traits were dominant. However, what we did not expect was the abnormal mutant that arose in a couple of our populations.

The conducted experiment assists in determining an unknown mutant allele found in Drosophila melanogatser. Mutant 489 illustrates a defect in eye pigmentation, which displays a dark brown eye color verses the brick red eyes in wild type flies. Based on the appearance our 489 mutation we've names our mutant rust.

The motivation of this lab report is to use Mendel’s Laws of Inheritance to analyze and predict the genotypes and phenotypes of an offspring generation (F2) after knowing the genotypes and phenotypes of the parent generation (F1). The hypothesis for this experiment is that the mode of inheritance for the shaven bristle allele in flies is autosomal recessive in both male and female flies.

It would be expected that the mutant F1 flies would be heterozygous for the allele responsible for the grounded trait. If two F1 flies were mated, the percentage of flies that would be expected to be wildtype in the F2 generation would be 25% mutants given that the mutant allele (ap) is predicted to be recessive and, leaving 75% to be wildtype (ap+).

There were eight different phenotypes among the progeny. The highest phenotypic frequency was the w+m+f+ at 40% of the progeny. The lowest was the w+mf+ with only 2 % of the progeny (Table 3). The sum of the recombinant frequencies between genes, table 4, was used to determine the gene distance. The recombinant frequency was determined by counting the number of individuals whose genes differed from that of the parental type. For example, how many individuals white eye gene, and miniature wing gene, differed from both wild-type or both mutants. Recombination occurred between the white and miniature gene 33 times. Recombination occurred between the miniature and the forked genes 31 times. Recombination occurred between the white and forked genes 44 time. Double recombination occurred 10 times. Therefore, genes w and f are 64 m.u. apart, m and w are 33 m.u. apart, and m and f are 31 m.u. apart (Figure

Table 2 shows the phenotypes of the F1 flies produced by crossing P1 wild-type males and P1 no-winged females. The results of that cross was that there was fifty nine wild-type females and forty one males. Therefore there was a total of one hundred wild-type flies produced from crossing P1 true breeding wild-type males and P1 true breeding virgin

11. The progeny of a Drosophila female (heterozygous at three loci: y, ct, and w) crossed to a wild type male are listed below:

For our first generation (F1) of flies we chose to cross apterous (+) females and white-eye (w) males. We predicted that the mutation would be sex linked recessive. So if the female was the sex with the mutation then all females would be wild type heterozygous. Heterozygous is a term used when the two genes for a trait are opposite. The males would all be white eye since they only have one X chromosome. If the males were the sex that had the mutation then all the flies would be wild type but the females would be heterozygous.

This experiment looks at the relationship between genes, generations of a population and if genes are carried from one generation to another. By studying Drosophila melanogaster, starting with a parent group we crossed a variety of flies and observe the characteristics of the F1 generation. We then concluded that sex-linked genes and autosomal genes could indeed be traced through from the parent generation to the F1 generation.

For each pair of traits crossed, one alternative was not expressed in the F1 hybrids, although it reappeared in some F2 individuals