High School Fruit Fly Lab

2. Place 10 randomly selected sowbugs in each of the 3 empty tin bowls for 3 minutes to allow them to acclimate to the environment.

It is possible that the temperature at which the flies were kept dropped significantly below 20 degrees Celsius; this could have caused the death of some of the files or slowed down their growth and reproduction rate. This would result in there being fewer flies. This problem could be overcome in further experiments by using a larger heating device with a more responsive thermostat to keep the Fly house within the recommended temperature range for D. melanogaster.

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.

We started out with three populations; B, D, and G. In order for us to properly create controlled genetic crosses, we had to ensure that all the female flies were “virgins”.

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:

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.

     There is a chance that there may be different outcomes to the F2 generation due to the possibility that the Line A and the Line B generation were not all homozygous dominant in wing type for females and eye color in males. Such a genotype in the males, vvBb, and such in females, Vvbb, may lead to a different ratio in the F2 offspring.

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

the definition of sex-linked genes, and examples of sex-linked genes in humans and other organisms

Usually 10 days of injections are necessary.When in the laboratory, surrounding cells are removed from the egg and the egg is prepared for fertilization. Inactive cells and seminal fluid are also removed from the males sperm in preparation for the treatment. The sperm and the egg are incubated together for about 18 hours. By this time fertilisation has usually taken place. Occasionally however, the sperm count is so low a single sperm is injected directly into the egg instead.

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).