Fruit Fly Lab Report

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.

To set up this experiment, two twenty-five gallon aquariums, 3 petri-dishes, 200 flies, rotten bananas, and yeast were used. The bananas chosen to be an accelerant for the growth of the yeast and were frozen so they would be easier to cut. The yeast was used because the drosophila melanogaster prefer this as a food source.  The vestigial and wild type flies were sexed (to determine their sex), sorted, and counted.  An initial population size of 100 total flies was decided so that it would be easier to determine the phenotypic percentage of the total population. Fly paper was placed in one of the sets of cages to impose a method of natural selection as well as the sexual selection which is being solely tested by the other set of cages.

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 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+).

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

The gender in this experiment does not matter and so while testing the ratios predicted it seems to be correct because since I predicted a 2:2 ratio the numbers seemed to be really close to each other. When I crossed the flies the vestigial and purple mutations were dominant over the wild type because in the end of the crossing the filial products were 620 for the vestigial and purple mutation, while for the wild type it appeared to be 618. My null hypothesis is that if the genetic characteristic of the fruit flies tested are not linked, then the vestigial wings and the purple eye mutations in the alleles of the offspring flies will be recessive to the wild type flies. My alternate hypothesis is that if the fruit flies tested are linked, then the vestigial wings and purple eyes mutations in the alleles of the offspring flies will be dominant to the wild type flies. The observations that led me to this conclusion is that when following the procedure of the experiment, I observed that my hypothesis is correct because when I finished crossing the fruit flies.

7. Second week: Begin by observing the F1 flies. Immobilize and examine all the flies. Record their sex and phenotype. Place as many F1 flies in a fresh culture bottle. For this cross the females need not be virgins. Label the vial with the symbols, name, and date.

Fruit Fly experiment was conducted by using different techniques. One of the main things was to examine the fruit flies and identify the difference between females and males, identify their mutation if they were wild type, white eye, vestigial or white and vestigial combined together. These Fruit flies were kept in the incubator at 25°C for about 6 days. The main goal for this experiment was to observe the principles of Mendelian genetics.

We will use Punnett Squares to find out the genotype and phenotype in the offspring of the fruit flies. Our experimental hypothesis of this experiment is that the genes of the fruit flies are linked, where the body color of the fruit fly is dark (b) recessive or light (B) dominant and type of wing, normal wings (W) dominant and abnormal wings (w) recessive is linked. The null hypothesis is that there will be an unlinked ratio for the phenotypes if the loci was

Introduction For centuries, researchers have used Drosophila melanogaster, the common fruit fly, to study genetics. The benefits of using the fruit fly includes: its relatively short generation time, its large amount of available offspring for data, it is easy to store and handle in the laboratory and it is easily and cheaply obtained. Cross-breeding of four types of fruit flies were used in this experiment including: wild type males with normal wings vs. vestigial wing females, wild type males with red eyes vs. white eyed females, wild type male with red eyes vs. sepia eyed females, and wild type males vs. wild type females. In basic mendelian genetics, the terms dominant, recessive and sex-linked are used to describe the different types

This determination was mainly so the group could easily spot the sex and traits of the flies for later steps. This was done to all four tubes of the P generation, all of the adult females were placed disposed of roughly 30 males from the wild type were kept in a separate jar. The adult females were not wanted because the females could have already mated with the males and the group needed the control of the transfer of genetics for the test crosses. The new virgins were born and collected approximately eight hour after the removal of the adults and placed into separate jars labeled by the genotype of their parents. After the process was done and 5-6 virgin females were collected the process could continue in order to cross still the P generation.

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.

We then kept the vial with the juvenile Drosophila for another 2 weeks in the same conditions as above and found that the F1 generation had hatched and laid eggs of their own. We then decanted the F1 generation into alcohol to kill them and kept them aside to score. The vial containing the new generation F2 of Drosophila was then kept for use in a further experiment.