Introduction Drosphila melanogaster, commonly known as the fruit fly, is an excellent organism for genetics studies because it has simple food requirements, occupies little space, is robust, completes its life cycle in about 12 days at room temperature, produces large numbers of offspring, can be immobilized readily for examination and sorting, and has many types of hereditary variations that can be observed with low-power magnification. The fruit fly has a small number of chromosomes (4 pairs), which are easily located in the large salivary gland cells. As mentioned before, the fruit fly life cycle is complete in about 12 days. First, a fertilized adult female must lay the egg, which leads to the first stage of the fruit fly life cycle, the egg stage. This first stage consists of a small, oval-shaped zygote with two filaments at one end. They are typically laid on surfaces of the vial and last for only about a day in optimal conditions. The egg, after a day, will then hatch into a larva, which marks the start of the larva stage. Lasting for about 3 days, the larva stage is broken up into three different segments: the first instar larva, second instar larva, and third instar larva. Throughout these stages, the wormlike larva eats continuously. A cream colored or white, wormlike organism with no legs or eyes except for hook-like mouthpiece for feeding. The larva feeds in the food medium for about 3-6 days then it leaves the food source in search of dry place to pupate. The first instar larva lasts for about a day or two, during which it mostly feeds the entire time, then the larva sheds its outer skin (cuticle) and enters the second instar stage, where it is bigger and more defined. From there, it repeats the same process as the first instar. …show more content…
The two most easily seen differences between male and female fruit flies are abdomen shape/size and sex
Throughout this experiment a number of random and procedural errors were apparent; these errors could have affected the results of the experiment in a number of ways. One experimental error that occurred during the experiment was that some flies became stuck in the food source and died. The main cause of this was the fact that the fly vials were stood up (vertically) before the flies had fully recovered from the anaesthetic. This could be overcome in future experiments by ensuring that the vials are kept horizontal until all of the flies fully recover from the anaesthetic.
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.
It was decided that there would be 80 vestigial flies and 20 wild type flies to total to an initial population of 100 drosophila. Next, the flies were anesthetized flies using Fly Nap. The flies were counted out to reach desired ratio, sexing the flies making sure there are equal amounts of males and females to be sure there is ample individuals to allow successful mating. The fly’s food was prepared by taking a frozen rotten banana, cutting it in half, mashing up the banana meat, and mixing yeast into it. The
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.
Drosophila Melanogaster, commonly known as fruit flies, are highly important model organisms in pertaining to biological research. The logic behind their recurrent use is due to their: easy culture in the laboratory, brief generation time, and ability to produce large numbers of offspring. In this report, we created isolated virgin D. Melanogaster from the original three populations we were given and then created crosses between them. Upon observation, we noticed an unusual mutant that arose from two of the three created crosses. We suspected that this genetic mutation had previously been discovered and named.
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+).
The results of this cross was that there were thirty eight wild-type females and thirty five wild-type males. Therefore there were seventy three wild-type flies. There were sixteen no-winged mutant males and eleven no-winged mutant females. Therefore there was a total of twenty seven no-winged flies produced in this cross. The observed phenotypic ratio of wild-type flies and no-winged mutant flies was 2.7:1 (winged: no-winged).The predicted phenotypic ratio if the no-winged mutation was autosomal recessive would be 3:1 (winged: no-winged). The χ2 value obtained for this cross was 0.213. The p value that was obtained for this cross was
11. The progeny of a Drosophila female (heterozygous at three loci: y, ct, and w) crossed to a wild type male are listed below:
Purpose The purpose of this experiment is to determine whether the fruit flies were dominant/recessive or linked/non-linked. The traits I chose for this activity was the fruit fly with vestigial wings and purple eyes, the other fruit fly I chose was a normal fly, also called wild type. While writing out my plan for this activity I thought it would be interesting to test a female mutant and the wild type male, the ratios I came up for this experiment was 2:2 and the mutant allele being recessive to the wild type. In this case, the words recessive and dominant means, if the child born from the parents inherits more of the genes and traits from let us say the father then the alleles of the father is dominant over the mother’s genes.
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.
Both males and females are affected with this gene, making it autosomal. This mutation results in a light brown-pigmented eye instead of the red wild type eye. This is due to the lack of pigments in the eye that would normally give rise to the wild type eye color (Lloyd 1998). The eye color darkens when the fly starts to age. Although, this mutation primarily affects the eye color, it also changes other parts of the body. For example, the malphigian tubules are a pale yellow. The fly’s testes and vasa become colorless during their adulthood. A possible chromosomal effect on phenotype occurs when alleles are recessive. When these homozygous recessive alleles are present in a fly, they are
In this experiment, there are many techniques to amplify and clone a gene from the fruit fly, Drosophila. The gene will be a homolog of a human gene that is important for this research. Ten homogenize files and KAc/LiCl working solution was used for the genomic DNA extraction. The buffer that was used contained ddH2O, Tris/Hcl pH7.6, EDTA, NaCl, and SDS. Cells are broken down so that the solution can release DNA.
Introduction Have you ever wondered how specific traits are passed down from generation to generation? Or if you already know the answer to that question, then how can you determine which traits are dominant and recessive. Finding both answers can be obtained by studying genetics. Reading about these topics only gives you a grasp on how traits work. In a laboratory setting, the answers can be found in an experiment using an unlikely specimen, known as the common fruit fly and its scientific name, Drosophila Melanogaster.
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.
The vial was then labeled accordingly with the type of cross (Male Vg, Female W) and the date. The date is important as the Drosophila complete a life cycle within approximately 2 weeks from the mating day. This vial became known as the parent generation or (P).