Mendelian Genetics Worksheet

Mendelian Genetics Lab Worksheet 1) Upload a photo of your Segregated Com Ears with yourself in the photo. 2) Part A Questions A1) Complete this Punnett square for a Rr x Rr cross for com kernel color. R R RR Rr Rr A2) What is the expected phenotypic ratio of the offspring in the above cross? The expected phenotypic ratio of the offspring would be 3:1 with 75% being purple kernel and 25% being a yellow kernel.. A3) Calculate and record the phenotypic ratios for your corn ear (this is actual observed data when you consider 100 corn kernels). In 100 kernels of corn, there were 66 purple kernels and 34 yellow kernels, 66:34 A4) How did your data compare with those that you predicted (compare answers from questions A2 and A3)? The ratio of yellow kernels out of the 100 kernels counted comes to a ratio of 33:100, 1 expected to see about 25% of the yellow corn allele phenotype and I think 33:100 is close to that. A5) Why do you expect class data to be closer to the expected ratio than data from your individual corn ear? I would expect the class date to be closer to the expected ratio than my individual corn ear because there are different amounts of yellow kernels produced in different ears of con that other students may have been assigned. Having this variety could allow us to see how ratios differ from this ear of corn and if they follow the expected outcome of the phenotype ratio. This gives a bigger sample size and less variation which would give us more accurate results of the expected ratio and data. A6) What is the genotypic ratio for the cross in question AI? The genotypic ratio for the cross in question Al is 1:2:1 A7) How would you test whether a purple com kernel has the genotype RR or Rr. Since the purple allele is the dominant allele in the case of these corn kernels, I would assume that in this ear of corn, the dominant trait is the one that is more common. In order for the dominant trait to be expressed, it would need to have the allele Rr or RR to express a purple kernel. A8) If a child is born with Cystic fibrosis, what are the expected phenotypes of each parent? What are the expected genotypes of each parent? The expected genotypes for the parents would be Rr for each parent. A9) Referring to the parents in question A8, what are the different gametes each parent can produce? The female parent would give XX gametes and the male parent would give XY gametes. A10) Referring to the parents in question A8, what is the probability of them having normal children? Children with cystic fibrosis? Express your answer in a phenotypic ratio. The phenotypic probability of them having normal children would be 3:1. The phenotypic probability of them having a child with cystic fibrosis is 1:3. All) The couple in question A8 has had three children without cystic fibrosis. If the couple has a fourth child, what is the probability that it will have the disorder? The probability of them having a child with cystic fibrosis will still be 1:3. A1Z) Considering the gene for deafness, construct a Punnett square for a homozygous recessive father and a heterozygous mother. Mother D d d d Dd dd Dd dd A13) For the cross in A12, what is the phenotypic ratio of their offspring? What is the genotypic ratio of their offspring? The phenotypic ratio of their offspring is 2:2 of being Deaf. The genotypic ratio of their offspring is also 2:2. 3) Part B Questions B1) Calculate and record the phenotypic ratios for your corn ear (this is actual observed data when you consider 100 com kernels). The phenotypic ratio for the corn ear is 1:3 purple wrinkled: round kernels and 1:8 yellow wrinkled: round kernels. B2) How does your observed ratio compare to the expected phenotypic ratio of 9:3:3:17 The numbers of the ratio are within the expected range. B3) Construct a Punnert square using the dihybrid cross PpGgPpGg. (PP, Pp codes for purple flowers, pp for white flowers; GG, Gg codes for green pods, gg for yellow pods.) Number the boxes from left to right, starting at the top. Pp Gg Pp Gg PpPp GgGg PpGg GgGg B4) Describe the phenotype of boxes 1, 3, 9, and 16.