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The Cross Of Straight Winged Fruit Flies

With Nubbin Winged Flies Essay, Research Paper

The Cross of Straight Winged Fruit Flies with Nubbin Winged Fruit Flies

The Cross of Straight Winged Fruit Flies with Nubbin Winged Fruit Flies

In 1933, a man named Thomas Hunt Morgan won the Nobel Prize for conducting experiments on genetics by using the Drosophila melanogaster (also known as the fruit fly). This experiment gave him the understanding of sex linked inheritance. The reason why he used fruit flies was because they breed many times and to have a good experiment you should have many results to work with.

Thomas Hunt Morgan was an American zoologist. He was a professor of experimental zoology at Columbia University. From his experiments he concluded that the individual units of heredity, (genes) are arranged in a line on the chromosomes. This theory, known as the chromosome theory of heredity. Morgan also wrote The Theory of the Gene in 1926.

The fruit fly has very few stages in it s life cycle. They are egg, larva, pupa, and then it becomes an adult. The female lays the egg and after one day the egg hatches and a larva comes out. The larva will keep eating for seven days and then it becomes a pupa. It will remain this way for six days and then finally it is an adult. Then the females are virgins for 8 to 12 hours. Once they reproduce with a male the female can store his sperm for the rest of the her life.

Genetics is an important aspect of many areas of pure and applied biology. Viral genetics, microbial genetics, plant genetics, animal genetics, and human genetics focus research on specific types of organisms. Research in molecular genetics involves studies on chemical structure and function; cytogenetics on location of the genetic material in cells and on cell division; developmental genetics on the genetic function in embryological phenomena; behavior genetics on the role of the gene in regulating behavior; and population genetics on the evolutionary process.

At the applied level, genetics is of direct use in understanding genetic diseases and environmental mutation. It is used in plant and animal breeding to improve the quality and quantity of food. It also is a tool in basic research by which complex biological processes can be analyzed, often at the molecular level

There are many aspects to apply to this experiment. This experiment was reproduced so that one can find out how genes can show up over other genes. Its almost like the gene conquers the other but lets it live. In other words the dominant gene shows up but the recessive gene is hiding it characteristics.

During this experiment the flies will mate with each other and come out with offspring. After I take my offspring and breed with a partner and decide what type off gene I want to look for. In my experiment I hope and think that straight wings are dominant to nubbin wings.

Procedure: Here is the order of operations that you must follow.

Culture Tube

1. Scoop a rounded teaspoon of medium into the bottom of your culture tube.

2. Add a couple of teaspoons of water until it turns completely blue. Make sure not to make it to wet because it will become mushy.

3. Add a little pinch of yeast onto the top of your medium.

4. Take one piece of netting and fold in half twice. Then place it into your tube.

5. Place one foam stopper on top and if you can get a blue top on, use one.

6. Take a piece of tape and place at the top. On the piece of tape write your name, period at what type of flies that you are crossing.


1. Take ether and put just a little of ether on the foam. Make sure to put stopper back on to the ether bottle.

2. Take stopper off of the chamber and tap your tube so you can put them into the chamber. Make sure you get them all into the chamber.

3. Put the stopper over the chamber and let your flies sit in their for about 2 minutes.


1. Take a microscope and place flies onto a piece of paper. Put under microscope.

2. Use the lowest magnification power and look at your flies.

3. Use a paint brush to separate you flies and make sure that they don t wake up before you are done.

4. It will be a male if it has a large hair on its front leg.

5. Males also have a darker abdomen than the females.

6. When you are done sexing your flies, place them back into your culture tube but, place them on the side of the tube.


During this experiment there are many safety procedures that one must follow. Do not inhale the ether because it is very bad for you. When you are taking off your foam top place upside down so you won t contaminate the tube. During the period of this experiment your tube is able to get mold inside of it. If this happens, you will have to start the tube all over.


Overall this experiment was a pretty good success. It showed that straight wings are dominant to nubbin wings and neither one are not sex linked, just like my hypothesis. The fruit flies that were used in this experiment are heterozygous but we can t tell by looking at the phenotypes. We can use common knowledge to figure it out but we need to look at their chromosomes to find the real answer. The reason why we know this is because if one parent gives a dominant gene and the other gives a recessive gene, then that would make the flies heterozygous for straight wings.

There was one major reason why this experiment was performed is, because Homo sapiens (humans) have genes and traits that are passed down from generation to generation, but the reason why we didn t use human traits is because there are 23 chromosomes and that there are more then one trait per chromosome. That would be to complicated to keep track of and it would be all most impossible to do crosses like dihybrid and trihybrid. Every day our body s cells go through mitosis and meiosis. Our cells double all of the time and they pass down their traits but we can t really see that. When we reproduce with another mate, we pass have of our genes down to meet with the other half from the mate. So why aren t our children the same as us? The reason is because we have genes that are dominant, comdominant, and recessive. The dominant genes with show up over the recessive. Codominant traits with blend together to come up with a trait that is in-between. Also, the genes come from both parents, and neither parent looks the same. The child is a mixture of each parent. Some children look more like one aren t because of their looks, but inside the could have a kidney disease from the other parent without anyone knowing it.

After trying and completing this experiment successfully, this shows why genetics are so important in our lives. Maybe one day they will figure out how to cure AIDS by using a certain trait that controls the immune system.