On to lose your great new job as a geneticist, because your boss thinks you mess

Question

On to lose your great new job as a geneticist, because your boss thinks you messed up an experiment while performing the Ames test. You are testing a delicious flavor additive called BSC1222 and the Ames test showed it was not a mutagen. Yet when this flavor additive was fed to mice, there were very high rates of the rats developing cancer. Explain why the Ames test did not accurately predict the potential of this flavor additive. Use a Chi-square test to determine whether the data below a Mendelian pattern of inheritance. Show all work. State your specific null hypothesis for this experiment and give Chi squared calculated and Chi squared table values. State whether you accept or reject this null hypothesis and state why An experiment to determine the inheritance of flower in snap dragons. you crossed two plants with pink flowers. color SHOW ALL WORK FOR CREDIT You know that one gene control flower color. 84 plants had red flowers, 172 had pink flowers, 78 had white flowers.

Explanation / Answer

3.Background:

The Ames test was developed in the 1970’s by Bruce Ames, Professor of Biochemistry at UC-Berkeley, as a fast and sensitive assay of the ability of a chemical compound or mixture to induce mutations in DNA.The test is done using bacterial cells because of the genetic similarities between the bacterial cells and human cells and to be able to test without harming animals.

Since DNA is chemically the same in all organisms, any living organism can be used to test for mutagens. Thus, bacteria can be used as a first step in identifying potential human carcinogens without waiting for long-lived mammals to develop cancer.

Answer: Since Ames test uses a bacterial cell to test the flavour compound and the bacterial cell does not have a complicated system of breaking the flavour compound to form metabolites, the test was neagative for mutagens. But when the flavour compound was tested on mice, the flavour compound brokedown in the liver to form carcinogenic metabolites which resulted in cancer.

4. The genetic situation is as follows:/

Red: WW

Pink:Ww

White:ww

Experiment as stated in the question is related to the cross between 2 plants having pink flowers

Monohybrid cross expectation is 1/4 Red 1/2 Pink 1/4 white

Results:

The degree of freedom is given by number of rows or expected frequency -1

here it is 2

Therfore the calculated Chi square is 6

Therefore 6>4,Reject the Hypothesis

Genetic Conclusion:

There is enough evidence from this experiment to conclude that Red flower color in snapdragons does not have Partial Dominance Inheritance.

Phenotype Observed Expected O-E (O-E)2 /E Red 84 86 2 2 Pink 172 172 0 0 White 78 86 8 8 Total 344 344 10 10

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