Wild Type And Ebony Lab Report

The Cross between Wild Type And Ebony
Introduction:
In 1909, Professor Morgan studied genetic change with Drosophila melanogaster, or fruit flies. Because of him, fruit flies have become popular for genetic research. Since fruit flies have a high reproductive rate and short life cycles, they are ideal for the study of genetics. The generation takes about 10-15 days to be complete depending on the temperature. Ideal temperatures range from 20-25°C, where 25° reduces the days it takes for an egg to turn into a larva. However, exposure to temperatures significantly higher or lower may result in death or imparities. There are several ways to distinguish the sexes. Females are generally larger than males. Females have seven segments in
their body, while males have five. Also, females have long abdomens that have a point, while they are more rounded in males. Their most distinctive characteristic is the sex combs, which are only found on the forelegs of males. In this experiment, it is important to note that females only remain virgins 8-10 hours after undergoing pupation. (Demerec and Kaufmann) The flies used in this experiment are wild type and ebony. Wild type flies are the type that is found most often in nature. Ebony flies are recessive mutations that have black bodies. (Fruit Fly Phenotypes)
Hypothesis:
The cross between ebony and wild type would result in wild type flies because it’s dominant.
Material List:
Fruit Flies
Fly Food
Petri Dishes
Magnifying lenses
Brushes
Vials
Fly nap
Procedure:
F1 Generation:
1.
Vitals of the flies should be ordered from a biological company.
2. Use fly nap to put flies to sleep.
3. After a few minutes, these flies should be asleep. Remove them from the vital into a petri dish. With a soft brush, separate the boys from the girls.
4. Place and label males into a new vital with fly food.
5. Kill the remaining female flies by placing them in alcohol. These are assumed to be non-virgins, which are needless in this experiment.
6. Within the next few days, observe the larva that are left in the original vital. When flies emerge, use fly nap and separate the sexes again in a petri dish.
7. The females should be virgins if they were carefully observed and separated 10-12 hours after pupation. These females are kept and placed and labeled in a new vital with fly food.
8. The males can be placed in the vital from step 4.
9. The result should have 4 vitals. A virgin female and male vital for ebony and a virgin female and male vital for wild type. These are the F1 Generation that will be used to create the F2 Generation.
F2 Generation:
1. Cross opposite sex of ebony and wild
type.
2. Place them in a new vital with fly food.
3. Observe the offspring and record the data.
Data:
Data from the Cross of Wild Type x Ebony

Female
Males
F1 Generation
1 Ebony
2 Wild Type
F2 Generation
9 Wild Type
1 Ebony female (from F1)
11 Wild Type
(2 of which were Wild Type from F1)

Punnett Squares:
F1 Generation

W+
W+
w
W+w
W+w w W+w
W+w
F2 Generation (W+w x W+w)

W+ w W+
W+w
W+w w W+w ww Calculations:
Observed: 8 Wild Type Female, 9 Wild Type males (17 total)
Expected: 4/4 *17 = 17 Wild Type
Percent ChangeL 17-17/17 * 100 = 0%

Conclusion: My hypothesis was correct because the offspring of F1 was all wild type. The results demonstrate that the wild type allele is dominant of ebony since there were no ebony offspring. The percent error shows that the result of the experiment is accurate to what is expected. If I were to do this experiment again, I would remove the F1 generation from the vital so that it wouldn’t be part of the F2 generation when they emerged. Work Cited: Demerec, M., and B. P. Kaufmann. Drosophila Guide. Washington: Carnegie Institution of Washington, 1957. Print. "Fruit Fly Phenotypes." Fruit Fly Phenotypes. UNC Baccalaureate Education in Science and Teaching, n.d. Web. 27 Oct. 2013. .