LAB 7 v2 - LAB 7 NOTE: These labs are known for high...

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LAB 7 NOTE: These labs are known for high failure rates. Therefore, if I show an example using data, a graph, etc… yours may be totally different depending upon mine and yours success with the lab. So don’t freak if your data is completely different from mine. And therefore the analysis of results sometimes may need to be answered differently since you base your analysis off your data and not mine. DISCLAMIER: DO NOT CHEAT! Introduction Drosophila Melanogaster , the fruit fly, is a great organism for genetic use because it has simple food requirements, occupies little space, is hardy, completes its life cycle in 12 days, makes a large number of offspring, can be knocked out easily, and it has many types of hereditary variations that can be seen with low power microscopes. Drosophila has a small number of chromosomes, four pairs. They are easily located in the large salivary glands. The Drosophila can be obtained from many places. Research of Drosophilae has led to a lot of knowledge about many of its genes. Many factors combine to affect the length of the Drosophila life cycle. Temperature affects the life cycle the most. At room temperature the average life cycle of the Drosophila is about 12 days. Eggs of the Drosophila are small, oval shaped, and have two filaments at one end. They are usually laid on the surface of the culture medium, and with practice, can be seen with the naked eye. After one day the eggs hatch into the larva. The larval stage of the Drosophila eats all the time. Larvae tunnel into the culture medium when they eat. The larva will shed its skin as it increases in size. In the last of the three larval stages, the cells of the salivary glands contain giant chromosomes that can be seen under low power in a microscope. The pupal stage. Before a larva becomes a pupa it climbs the side of the container. The last larval covering then becomes harder and darker, forming the pupal case. Through this case the later stages of metamorphosis to an adult fly can be seen. In particular, the eyes, the wings, and the legs become visible. The adult stage. When metamorphosis is over, the adult fly emerges form the pupal case. They are fragile and light in color and their wings are not fully expanded. They get darker in about an hour. They live about a month and then die. A female refrains from mating for about 12 days after she emerges from the pupal case. After she mates her receptacles contain large amounts of sperm and she lays her eggs. Make sure that the first flies you use are virgins. The experiment will take several weeks. You will be assigned Drosophila with well- defined mutant traits by your teacher. You will keep a close record of what happens as each of these flies mate and pass there traits off to their offspring over a few generations.
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There are three types of crosses that are studied in this lab. In monohybrid crosses the mode of inheritance is determined when a single contrasting pair of characteristics is involved. In a dihybrid cross the mode of inheritance is determined when the two pairs of
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LAB 7 v2 - LAB 7 NOTE: These labs are known for high...

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