Drosophila Melanogaster: Predicting Traits Lab Report
The purpose of this study is to get an accurate look on how genetics work, and to practice determining the different traits within the species. D. melonogaster are useful because they are easily cultured and they reproduce very quickly. The eye color data supports past genetics problems because it can be predicted, and used in Punnett squares to aid in the prediction. If the P generation consists of a purebread red eyed fly(dominant) and a purebread sepia eyed fly (recessive), then the F1 generation will be heterozygous and produce an F2 generation with mostly red eyed, but some sepia eyed flies.
Prediction: Since the P generation and its F1 offspring is red eyed, and the F1 generation had some heterozygous flies, it can be predicted that the eye color is an autosomal trait. Also, certain colors are not restricted to a certain gender. Red eye color is most likely dominant because the P generation was a purebread red, and a purebread sepia fly, and their offspring was all heterozygous red. It can also be predicted that through the generations, the dominant eye color will be red, though the recessive sepia color will eventually appear.
• Drosophila Handbook
• D. Melanogaster flies
• Fly Food
Methods:Independent Variable: Parental (F1) Eye Color
Dependent Variable: Offspring (F2) Eye Color
Control Group: Punnett Squares
Controlled Variables: Same food, living quarters, species and Flynap. 1. Observe phenotypes of the flies in your given vial.
2. Fill out a label for your new empty vial.
3. Place the label on the new vial.
4. Wait for teacher to feed flies.
5. Place the first vial on its side and gently transfer 5 male and 5 female flies into your new vial. 6. Put plug in your new vial. Leave the vial on its side at the table. 7. Wait several days for the F1 flies to mate and lay eggs, then remove the parent flies. 8. Wait for F2 offspring to become adult, and then count the number of male and female offspring and their eye color. Record information in a table. Results:
Group Offspring Count
|Lab Group- Pd. 7 |Total Count |Red Eyes |Sepia Eyes | |7 |184 |162 |22 | |Percentages |100% |88% |12% |
Class Offspring Count
|Lab Group-Pd. 7 |Total Count |Red Eyes |Sepia Eyes | |1 |99 |86 |13 | |2 |115 |83 |32 | |3 |115 |94 |21 | |4 |118 |93 |25 | |5 |174 |131 |43 | |6 |160 |132 |28 | |7 |184 |162 |22 | |Total # of Flies |965 |781 |184 | |Percentages...