Name: Bhavi PatelPartners: Subhrangi Swain and Jessica GreenTitle: GeneticsDate of Experiment: 10/20, 10/27, 11/3/2011Due Date: 11/18/11Experiment #4, 5, 6Abstract: The purpose of this lab was to determine the genotype of the mutant we used to do ourcrosses. We started off by crossing long B hermaphrodites with normal males. Based on the observation and data we received from the initial cross we determined that this mutation was x-lined recessive. To confirm this hypothesis we conducted two more tests, one of which replicatedthe previous two crosses and another which was done between the f1 off-springs. The results from the second set of crosses reinforced our hypothesis that this mutation was x-lined recessive.Introduction: Over the years, Caenorhabditis elegans are used many times when studying genetic control of development and behavior because they are not a complex structure and therefore are easy to take care of and examine when dealing with genetics, “The life cycle of thisworm is approximately 2-3 days at room temperature but can be slowed to a week if raised at a lower temperature. The worm is small and transparent, with a limited number of cells making complete anatomical studies easy and inexpensive” (lab protocol). There are two types of C. elegans, “hermaphrodites and male, hermaphrodites can self-fertilize, however the male needs to mate with hermaphrodites to produce offspring”(lab protocol). In this lab, we looked at the four different types of mutation C. Elegans have, which include N2 wildtype, dumpy mutants, small mutants, and long mutants. With this information we performed crosses between normal males and hermaphrodites to figure out their genotype and find their inheritance pattern. There are fourdifferent types of inheritance patterns, which include autosomal recessive, x-linked recessive, autosomal dominant, and incompletely dominant. My group hypothesized that if we crossed hermaphrodites (Long B) with a male then the offspring would be A) Autosomal recessive if the F1 generation would have either all normal or half normal andhalf hermaphrodite Long B.B) X-linked recessive if the F1 generation would have all long males and normal hermaphrodites.C) Autosomal dominant if the F1 generation would have either all long or half would be long and half would be normal.D) Incomplete dominance if the F1 generation would have all medium sized worms. In addition to this, based on our observation from our first cross of the long B hermaphrodite with normal male we hypothesized that if the long mutation is x-linked recessive the offspring males of the F1 generation would be longer than the normal. However to further support our hypothesis we decided that if we did a second cross with the F1 generation worms, then we would get 25% of each type of worm. Methods: At first, my group observed the hermaphrodites and normal males under the microscope and we used the spatulas to practice picking up and moving the worms from one plate to another. Then we took normal males and Long B hermaphrodites to cross, we did this by using the spatula to pick and transport 6 normal males from one plate and 3 Long B hermaphrodites from another plate and placed them on a new plate to see their F1 offspring. We then left the plates for the duration of one week to allow them to reproduce. When we came backwe counted the number of each type of worms we had and recorded the data. We then did a second cross using the F1 generation long males with normal hermaphrodites by picking them upwith a spatula and placing them on a plate with each other. Next, we took 6 normal males and 3 Long B hermaphrodites with a spatula and transported them onto a new plate. Then we left these plates for a week to reproduce. When we came back we counted the number of each type of worms and recorded our data. Then we determined the inheritance pattern of the mutant and cleaned our area. Results: My group concluded that the mutant is x-linked recessive because for it to be x-linked recessive the cross would look like the following: Figure 1: x-linked recessive genotypeMale: X^rOHerm: X^rX^r X^R O X^r X^r Therefore all of the males would be mutants. In addition to this, we counted all of the types of worms we had after each cross and received the following data:Table 1: Number of the different offspring Long herm Long male Normal herm Normal malePlate 1(normal male w/ Long B herm)Plate 2 (normal male w/ Long B herm)Plate 3 (normal male w/ Long B herm)Plate 4 (Long male w/ normal herm)For the second crossing, based on our data we decided that the genotype would most likely be the following for the F1 generation: Figure 2: Predicted genotype of the F1 generationMale: long mutation (X^rO)Herm: normal (X^RX^r)X^r O X^RX^r X^rOX^RX^r X^rO0 50 35 00 25 16 00 29 24 026 30 40 28X^R X^rAnd because there was a about a 25% chance of getting all the types of worms for the with the F1 generation (Plate 4), we concluded that these mutants are x-linked recessive. Discussion: In the end, our results came out like we had predicted, and we concluded that these mutants are x-linked recessive, based on our observations and data. During our experiment we had said that by crossing Long B hermaphrodites and normal males we would get long males andnormal hermaphrodites, basically all male mutants, and in our data we saw that when we did this cross we got 50 long males and 35 hermaphrodites for plate one, 25 long males and 16 normal hermaphrodites for plate two, and 29 long males and 24 normal hermaphrodites for plate three. Then we had said that if we take the F1 generation offspring of either plate one or two, which is long male with normal hermaphrodites, we would get 25% of each type for the mutation to be x-linked recessive and according to our data we got 26 long male, 30 long hermaphrodites, 40 normal hermaphrodites, and 28 normal males, which is about 25% of each type, and this data lead us to our conclusion. However, we did have difficulty counting the worms because many of them were dead and many of the males were still developing. In addition to this, since there werea lot of normal hermaphrodites in our F1 generation cross,