Drosophila Fruit Fly Lab Report

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.

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.

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.

Describe the sex and phenotype of the mutant fly. Describe the phenotype as it compares to the wild type.

Table 1 shows the phenotypes of the F1 flies produced by crossing P1 wild-type females and P1 no-winged mutant males. The results of that cross was that there were forty seven wild-type females and fifty three wild-type males. Therefore there was a total of one hundred wild-type flies that were produced. The observed phenotypic ratio of wild-type flies and no-winged mutant flies was 1:0 (wild-type: no-winged). The predicted phenotypic ratio if the no-winged mutation is autosomal recessive would be 1:0 (winged: no-winged).

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

9. Fourth week: Begin removing the F2 flies. Record their sex and the presence or absence of mutation(s). The more F2 flies collected, the more reliable the data will be. You may have to collect flies over a three-or four day period (or more). Try to collect at least 200 flies (probably quite a bit lofty).

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

Heterozygotes, which have the wild type phenotype, have normal sight which gives them the advantage of finding a mate and have a better success with attracting a mate with their courtship song (Kyriacou et al, 1978). The male heterozygous Drosophila had a better advantage at mating than the homozygotes, which were the ebony, and therefore we predict there will be more wild type by the end of the experiment.

The Drosophila melanogaster is a fruit fly with a very short life cycle. They can be winged or wingless, and have red eyes or white eyes. The different options are called alleles. Alleles are the variants of a specific gene, and one is received from each parent on each chromosome. (“What Are Dominant and Recessive?”). It was chosen to use winged females and wingless males to predict the offspring in this experiment. The winged allele is dominant, meaning it only needs one allele to physically appear. The wingless allele is recessive, which gets covered up by the dominant allele (“Fruit Fly Genetics”). Each trait has two alleles in the flies’

we said goodbye and placed them in the fly morgue. We allowed the F2 larval

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.

Scientist use Drosophila melanogaster because they reproduce very rapidly and have shorter generations. These characteristic of being able to go through many generations in a short amount of time combined with its resemblance in behavior and development to a human made it a good candidateto use this organism to study genetics.

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.