A Study Of Inheritable Traits In Fruit Flies Essay -- fruit fly geneti

A Study Of Inheritable Traits in Fruit FliesINTRODUCTION The Drosophila melanogaster, more unremarkably known as the fruit fly, is apopular species used in genetic experiments. In fact, Thomas Hunt Morgan beganusing Drosophila in the archaeozoic 1900s to study genes and their relation tocertain chromosomes(Biology 263). Scientists have located over 500 genes on thefour chromosomes in the fly. There argon many advantages in using Drosophila forthese types of studies. Drosophila melanogaster can lay hundreds of eggs afterjust one mating, and have a generation time of two weeks at 21C(GeneticsDrosophila Crosses 9). Another reason for using fruit flies is that they maturerather quickly and dont require very very much space. Drosophila melanogaster has alife cycle of four specific stages. The first stage is the egg, which is about .5mm long. In the 24 hours when the fly is in the egg stage, legion(predicate) cleavagenuclei form. Next, the egg hatches to reveal the larva. During t his stage,growth and molting occur. Once growth is complete, the Drosophila enter thepupal stage, where it develops into an adult through metamorphosis. Uponreaching adulthood, the flies ar ready to mate and produce the next generationof Drosophila melanogaster. During this experiment, monohybrid and dihybrid crosses were conductedwith Drosophila melanogaster. Our objective was to examine the inheritance fromone generation to the next. We collected the data from the crosses and studythem in relation to the expected results.MATERIALS AND METHODSFor the monohybrid cross in this experiment, we used an F1 generation, whichresulted from the mating of a male homozygous wild-type eyed fly with a femalehomozygous sepia eyed fly. Males and females are distinguished by differences inbody shape and size. Males have a darker and rounder abdomen in comparison tofemales, which are more pointed. Another difference occurs on the forelegs ofthe fliesmales have a small bump called sex combs. At week 0, after beinganaesthitized by fly-nap, three males and three females were identified under adissecting microscope and placed in a plastic ampule with a foam stopper at theend. The vial remained on its side until the flies regained consciousness sothat they didnt get trapped by the culture medium at the bottom. We allowedthe Drosophila to incub... ...eighed the piece of males. This may imply that the X chromosomeis dominant over the Y chromosome. This would cause the X chromosome to motleywith another X chromosome, producing a female, more often than it would mix withthe Y chromosome, which would produce a male. As a follow-up to the experiment,I would perform many more trials than each person did for this experiment. Also,more flies could be placed in each vial to en authoritative even more offspring to beincluded in the data. I would also be sure to remove the flies after just oneweek to reduce breeding between generations. This experiment caused Mendelsfindings to be mo re concrete and naturalistic in my mind. It made the informationmore than meaningless numbers. The experiment also made me realize how easilybiological ideas can be proved. Our results agree with Mendels discoveries.The only drawback to our learning was the massacre of over 26,000 fruit flies.REFERENCESCampbell, Neil A., Biology Fourth Edition. Menlo Park Benjamin/Cummings,1996. Genetics Drosophila Crosses. Lab Handouts, General Biology Lab, 2008.So Whats a Monohybrid Cross Anyway? Lab Handouts, General Biology Lab, 2008.