Fruit Fly Genetics

Introduction

In this lab a study of fruit fly genetics was done these creature are readily used for genetic studies .they are easy to maintain. And the females lay a lot off eggs which develop in about two weeks. Fruit fly’s have for distinct stages, the egg, larva, pupa and adult. the egg and larva stages last for eight days, the pupal stage last for six days and then the adult stage which last for many weeks this period of growth is called instars. In this lab a dihybrid cross was performed to get data results and to draw a conclusion to the hypothesis.

The hypothesis for this experiment is that it will yield a 9:3:3:1 ratio XY, Xy, xY, xy. Which is that 9 out of 16 would have long wings red eyes, 3 out of 16 would have long wings brown eyes as well as 3 out 16 having short wings red eyes, and only one having short wings brown eyes. LR, Lb, Sr, sb.

Materials and methods

The class was given vials with adult fruit flies of P1 parent generation to look at the traits, one generation was homozygous, wild type eyes and dumpy wings. The other one was homozygous for sepia eyes and normal wings. These were crossed to yield the F1 generation which is crossed to produce the F2 generation.

Different variables were analyzed in this experiment. The independent and dependent variable for this experiment was the male fruit fly and the female fruit fly and the off springs. The controlled variables in this experiment were temperature, media, yeast, to much of the yeast would kill the fruit fly’s so the class had to make sure that to much was not poured into the vials. this had to be controlled well. 6- 10 ten grains of yeast with water and media. A change in temperature could also tamper with the experiment as well as messing with the vials all of these variables had to be controlled in order for the experiment to do well.

In order to view flies they had to be anesthetizing first then the class sorted them according to sex. The class used a dissecting microscope a white sorting card and a brush to go about this method 10 males and females where then poured into the cultured vial. This was done while the vial was on its side to make sure the fruit flies would not drown in media. After 7 days the adults were taking out so the F2 generation would not be confused,