If there is a gene with four alleles A1, A2, A3, and A4 then six distinct heterozygous genotypes are possible because A1 cross A2, A1 cross A3, A1 cross A4, A2 cross A3, A2 cross A4, A3 cross A4 will be formed and other will be similar so therefore only six genotypes are possible for distinct heterozygous traits.
This can be solved either by using a Punnet Square or you can use the formula (n(n+1))/2, where n is the number of alleles. However, using either method will give you the number of possible genotypes regardless if it's homozygous or heterozygous. If we use the second formula, that will give you 10 possible genotypes. Since you only want to know the number of heterozygous genotypes, you should subtract the number of possible homozygous genotypes. In this case, there are four. That is (A1,A1), (A2,A2), (A3,A3), and (A4,A4). Knowing this, you'd be able to figure out that there are six heterozygous genotypes.
The correct answer for the question that is being presented above is this one: "B. Perfringens food poisoning."
The correct answer for the question that is being presented above is this one: "<span>C. It is listed with the CDC as a notifiable disease in its annual summary."</span>
<em>The main reason such an elaborate device was used would be to eliminate any element of bias by the researcher.</em>
It is important to eliminate biases when taking measurements so as to ensure the accuracy of the data and the overall outcome of the experiment. <u>If a simpler device had been used in which the researcher manually records the length of the bones, it is possible to knowingly or unknowingly introduce biases or random error into the experiment which will impact the integrity of the data and the outcome of the experiment.</u>