Confirmation Of Mendel's Law Of Segregation

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Confirmation of Mendel’s Law of Segregation
I.
In Biology class the past few weeks we have been learning about Gregor Mendel. Gregor Mendel is often called the father of modern genetics. Mendel developed the theory of inheritance several decades before the observance of chromosomes via microscope. In Biology lab the past two weeks I completed a series of tests using fast plants, Brassica rapa. The objective of this experiment was to study the Mendelian laws of genetics as they applied to monohybrid and dihybrid crosses. I came up with two hypotheses said tests. The first being, the genetic trait of stem color is due to simple dominance and will follow Mendel’s Law of Segregation. Purple stem color is dominant to the green stem color.
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For my part of the Mendel Experiment, my lab group tested monohybrids. Our professor had the grow lighting system set up and waiting, as well as, the reservoirs filled with water. Complete with blue algae test squares. With this done, I was ready take a styrofoam quad and place one wick in each cell, careful to let the tip extend halfway out of the hole in the bottom. I then filled each quad cell halfway with soil and added two to three fertilizer pellets in each cell. After this I filled each cell to the top with moistened soil leaving a shallow depression on top for the seeds. Lastly, I placed three seeds in each cell, and then sprinkled a little soil on top to cover them. To complete this experiment I pipetted water to moisten the soil till water drips could be seen coming from each wick and labeled my lab experiment for reference the following week when we would gather …show more content…
In regards to the monohybrid cross test, I reject the null hypothesis because the calculated x² value of 13.241 is larger than the table X² value of 3.84 (df=1 & p=.05), therefore the observed distribution of purple and green stems is significantly different from the distribution expected under Mendel’s Law of Segregation which predicts the phenotype ratio of three purple stems to one green stem plants (ratio: 3:1). I also have to reject the null dihybrid hypothesis because the calculated x² value of 12.015 is more than the table X² value of 7.82 9df=3 & p=.05). The observed distribution of plants with purple stem and green leaves is significantly different from the distribution expected under Mendel’s Law of Independent Assortment which predicted a ration of nine purple stem/green leaf, three purple stem/yellow leaf, three green stem/green leaf, and one green stem/yellow plants (ratio: 9:3:3:1). There are a few reasons as to why this has happened to my results compared to those of students from previous years. One very plausible reason for have such drastically different results could be an error at the seed packing plant with the sample size pack. Another could be that this is a random

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