Fruit Fly Lab Report
Genetics of Organisms
Nicole Ryan
AP Biology 2/2/15 Block 1
Introduction and Background
Drosophila melanogaster or more commonly referred to as “fruit flies” have been used for genetic research for over 100 years. During his time at Harvard university, Charles W. Woodworth is credited with being the first to suggest fruit flies be used for genetic research. A century later, fruit flies are the most widely used eukaryotic organism for genetic research (Drosophila). Their ease of use and rapid rate of reproduction has allowed researchers across the globe further our knowledge of genetics. Measuring only a few millimeters in length, fruit flies take up a fraction of the room of other organisms …show more content…
Once the vials are prepared, begin placing in pairs of male and female flies into the correctly labeled vials. Use paint brushes for moving flies if necessary. Cap these vials and place them in a warm area. These flies will mate and produce the F2 generation
6. After the F2 vials have been sitting for approximately 10-12 days, remove the adult flies. By this time the flies will have mated and the female will have laid her eggs. Removing the adults will prevent F1 flies from mating with F2 offspring. To do this, carefully use Flynap (technique as described in step 1), being aware that fly larvae are more sensitive and may be fatally harmed by “over-napping”. Remove the flies by inverting the vial and placing the adult F1 flies in the “morgue” (a jar containing alcohol or baby oil). Then close the vial and allow it to sit for another 12-15 days.
7. After 12-15 days have passed, record the sex and phenotype of all adult flies. As described in steps 1-3 Flynap will be used to anesthetize the flies before they are removed from the vials to be put into petri dishes for counting. Once all of the flies have been counted and recorded, place them into the “morgue” and dispose of all …show more content…
The number acquired through the use of the equation is compared to the critical values table to verify or deny the null hypothesis. If the value is equal to or below that of the chart then the hypothesis is valid, if it is above the critical value then it is invalid. The null hypothesis for cross A was valid while the hypotheses for crosses B and C were invalid. (See Punnett squares, Chi-square analysis and null hypotheses located on pages 6-10) For this lab, the use of virgin flies was vital to producing accurate data. Since female fruit flies have the ability to store semen in their ovipositor, eggs can be fertilized with semen from any number of males that she has mated with. Because of this the use of virgin flies in the parental generation ensured that the offspring were products of the male and female of that cross with no contamination from other male flies. However, virgin flies were not required in the F1 cross because they were the only flies we had and would be crossed with each other anyway.
Nicole Ryan
AP Biology 2/2/15 Block 1
Introduction and Background
Drosophila melanogaster or more commonly referred to as “fruit flies” have been used for genetic research for over 100 years. During his time at Harvard university, Charles W. Woodworth is credited with being the first to suggest fruit flies be used for genetic research. A century later, fruit flies are the most widely used eukaryotic organism for genetic research (Drosophila). Their ease of use and rapid rate of reproduction has allowed researchers across the globe further our knowledge of genetics. Measuring only a few millimeters in length, fruit flies take up a fraction of the room of other organisms …show more content…
Once the vials are prepared, begin placing in pairs of male and female flies into the correctly labeled vials. Use paint brushes for moving flies if necessary. Cap these vials and place them in a warm area. These flies will mate and produce the F2 generation
6. After the F2 vials have been sitting for approximately 10-12 days, remove the adult flies. By this time the flies will have mated and the female will have laid her eggs. Removing the adults will prevent F1 flies from mating with F2 offspring. To do this, carefully use Flynap (technique as described in step 1), being aware that fly larvae are more sensitive and may be fatally harmed by “over-napping”. Remove the flies by inverting the vial and placing the adult F1 flies in the “morgue” (a jar containing alcohol or baby oil). Then close the vial and allow it to sit for another 12-15 days.
7. After 12-15 days have passed, record the sex and phenotype of all adult flies. As described in steps 1-3 Flynap will be used to anesthetize the flies before they are removed from the vials to be put into petri dishes for counting. Once all of the flies have been counted and recorded, place them into the “morgue” and dispose of all …show more content…
The number acquired through the use of the equation is compared to the critical values table to verify or deny the null hypothesis. If the value is equal to or below that of the chart then the hypothesis is valid, if it is above the critical value then it is invalid. The null hypothesis for cross A was valid while the hypotheses for crosses B and C were invalid. (See Punnett squares, Chi-square analysis and null hypotheses located on pages 6-10) For this lab, the use of virgin flies was vital to producing accurate data. Since female fruit flies have the ability to store semen in their ovipositor, eggs can be fertilized with semen from any number of males that she has mated with. Because of this the use of virgin flies in the parental generation ensured that the offspring were products of the male and female of that cross with no contamination from other male flies. However, virgin flies were not required in the F1 cross because they were the only flies we had and would be crossed with each other anyway.