Coin Sex Lab Relate and Review

In this lab, my partner and I flipped coins marked with specific alleles, different variations of a gene, on each side in order to see how probability is used to predict what an offspring genes would be. Coins serve as a model for genetics concepts for they have a 50% percent probability chance, which means they can represent alleles, and the coins together can represent the make up of the genetic material of the zygote, or fertilized egg. The first part of our lab, Sex of offspring, asked the question, "Can you predict whether you will have a boy or a girl?" We flipped two coins, which were either marked X or Y on both sides, simultaneously 10 times in order to get the genotype (XY, XX), thus also the phenotype (female or male). With the monohybrid cross, which is when homozygous dominant are cross with homozygous recessive, there is a 50% probability for having either a male offspring or female offspring. The ratio we got instead was 7:3 (male to female). Though our ratio was off, due to either determining the phenotype of a genotype incorrectly or not flipping the coins the right way, predicting the possibility of having a male or female child is possible, though the prediction might not be for sure. The second part of our lab, Autosomal Dominance, which is when the dominant allele is not sex-linked, asked the question, "If bipolar disorder does not run in your family, but you marry someone who has bipolar disorder, what is the probability that your children will have it? (Assuming spouse is heterozygous for the trait)" With the punnet square, we concluded that there is a 50% probability of the offspring having bipolar disorder. We used two coins, one labeled "b" on both sides and the other labeled "B" on one side and "b" on the other side. We then proceeded to flip the two coins simultaneously 10 times. Our ratio, though again off, was 8:2 (Bipolar individuals to nonbipolar individuals).Our actual result could've differed to our expected result due to errors in determining the phenotype of a genotype. We also found that our result was improbable. The third part of our lab, X-Linked recessive, asked the question, "Why do males have colorblindness more often than females? What is the probability of having a colorblind child if the mom is a carrier and the dad has normal color vision?" Before my partner and I actually started the procedure we decided to find out what X-linked inheritance was, we found that it was when an organism inherits the gene responsible for a trait from the x chromosome. Using the punnet square, we then moved on to find the probability which was 25%. Using two coins, one marked X^B on one side and X^b on the other side and one marked X^B on one side and Y on the other side, we found the genotypes and phenotypes by flipping the two coins simultaneously. The genotypic ratio we ended up with was 4:2:1:3. We also concluded that males have colorblindness more often than females because they control the x chromosome. Our actual result could've differed to our expected result due to errors in determining the phenotype of a genotype. In our dihybrid cross, where double homozygous dominant is crossed with double homozygous recessive, simulation, our expected result were 9 individuals with brown hair and brown eyes, an example of homozygous, 3 individuals with brown hair and blue eyes, an example of heterozygous, 3 individuals with blond hair and brown eyes, and 1 individual with blond hair and blue eyes; A phenotypic ratio of 9:3:3:1. Our actual results were 12 individuals with brown hair and brown eyes, 1 individual with brown hair and blue eyes, 2 individuals with blond hair and brown eyes, and 1 individual with blond hair and blue eyes. Instead of a 9:3:3:1 ratio, my partner and I got a 12:1:2:1 ratio. Our actual result could've differed to our expected result due to errors in determining the phenotype of a genotype or flipping the coins incorrectly. With these results, and the phenotypic ratio that my partner and I concluded to, I can attribute that the phenotypic ratio 9:3:3:1 does not apply to every case, though it is a good foundation to follow. Another important note to mention is how the Law of Independent Assortment was applied here. The Law of Independent Assortment states that gene pairs separate randomly or independently from each other during meiosis, the process of making gametes in testes or ovaries, in this case, the gene pairs were separated randomly/independently from each other in order to form the phenotypes (ex: BE, bE, Be, be). The limit of using probability to predict offspring's traits is that it is not a certainty and only predicts what the offspring's traits could possibly be, not what it will be for sure. Probability is just the number that an event can occur over the total number of possible outcomes while certainty is something that will actually really happen. Also, when the recombination of genes happen, something, in which the Punnet Square didn't predict, could occur. One way this relates to my life is it lets me understand how I got specific traits, like having my mom's dominant wavy hair trait and not my dad's recessive straight hair trait. It also lets me understand how there are cases in which people have green eyes while their parents have brown eyes because the green eye trait skipped a generation since it was recessive.