The goal of this lab was to find out the genotypes of the parent fruit flies. The life cycle of the fruit fly is about eight days in the egg/larva stage, six days in the pupa stage, and flies can live to be several weeks old. Differences between the male and female fruit flies are that males have hairs on their front legs and darker colored tail-ends. Females have fewer hairs on their front legs and lighter colored tail-ends. The three kinds of fruit flies were vestigial, white, and red. Vestigial flies have red eyes and short, kind of crumbled up wings. White flies have white eyes and longer wings. Red flies have red eyes and longer wings. We chose to cross female red flies and male white flies. We chose this cross because many others were using vestigial flies resulting in a shortage.

For my hypothesis I thought that there would be more flies with red eyes because there are two types of flies with red eyes so I thought they would be dominant, and since both types of flies we used have long wings, I guessed that all of our flies would have long wings.

We started out collecting each type of fly that we wanted to cross. Then we waited about three weeks for the flies to mate and have eggs. Then the next step would be to count the flies of each type and record the data.

Since our fly crossing resulted in too few new generation flies to count we were given an alternate source of data.

A cross of the new generation could happen with RrXRr, rrXrr, or RrXrr. From these crosses I would expect that from the first cross would result in 75% red and 25% white, from the second 100% white, and from the third 50% red and 50% white. The only problem I had with the experiment was that during the time we gave our flies to mate they didn’t and it resulted in very few flies. There is no real logical way to improve this problem so it’s just a variable that has to be dealt with.