Fruit Fly Essay

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BioL-2107L-197 Genetic study of Fruit Flies Fruit flies have the fastest life cycles, and these insects can change from egg to adult immediately in a few weeks. Since one female fruit fly can breed hundreds of eggs, they can easily multiply quickly. Therefore, they are a prime specimen to be studied in the laboratory for genetic studies. In 1910, Thomas Morgan chose fruit flies to begin his genetic studies and until this day, they are still an ideal model for study. There are many reasons that fruit flies are preferable to be studied because they are easy to be handled in the lab, they mate easily, hundreds of eggs can be laid by each female, the young grow in approximately ten to fourteen days, they are easily put to sleep, and they have only four pair of chromosomes. In the salivary gland, there are giant chromosomes called polytene chromosomes which are belong to larvae, and ordinary light microscope can be used to study these chromosomes. Besides this, there are many phenotypic variations available that can be distinguished easily for study. There are four stages in the life cycle of the fruit fly, and they are egg, larva, pupa, and adult respectively. According to the lab note book “the egg and larval stages last eight days, the pupal stage six days, and the adult stage for several weeks”. The day after the egg is laid, the larva hatches and peels twice shedding its cuticle. The time between the growth before and after peeling are called instars. Therefore, there are three instars in fruit fly. At the third instar, as it begins to pupate, the larva gets harden and darken as it attaches to the side of the vial. Then, the adult fly emerges after six days. Two days after emerging from the pupal stage, the female adult fly can start laying eggs. It is also important to know that to get a good result in the experiment, virgin females have to be used for most
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