Non-Mendel Genetics Practice

1a. Example problem is completed so you can see the complete example. Remember to put the first organism mentioned on the top of the Punnett Square so it can be graded correctly! Flower color in snapdragons is an incompletely dominant trait. The allele for red flower color is (RR) and the allele for white flower color is (WW). The heterozygous phenotype for these two alleles is a pink color (RW).Please fill in the Punnett square below and predict the genotypic and phenotypic ratios that will be observed by a cross between a Red snapdragon and a White snapdragon. Key: RR = red, RW = pink, WW= white R R W RW RW W RW RW 1b. Write the proportions, percents, and ratios for the genotypes and phenotypes of this cross*If the proportion or percent is zero, put a zero in those blanks Genotype:Proportion = 0 or 0%RW = 4 or 100%WW = 0 or 0%Ratio: N snapdragons = 0 or 0%Pink snapdragons = 4 or 100%White snapdragons = 0 or 0%Ratio: N 2a. Incomplete Dominance One of the pink offspring from the cross above is crossed with a white snapdragon plant. Please fill in the Punnett square and the genotypic and phenotypic ratios for this cross below. (blank) R W W RW WW W RW WW 2b. Write the proportions, percents, and ratios for the genotypes and phenotypes of the above cross (if there are none put 0 in the blank) Genotype:Proportions = 0 or 0%RW = 2 or 50%WW= 2 or 50%Ratio: 1:1Phenotype:Proportions snapdragons = 0 or 0%Pink snapdragons = 2 or 50%White snapdragons = 2 or 50%Ratio: 1:1 3a. Speckled Chickens-- Codominance Feather color in chickens is a codominant trait. The allele for black feathers can be written as (B) and the allele for white feathers can be written as (W). The resulting phenotype of the heterozygous genotype is a black and white speckled chicken (BW).Please fill in the Punnett square below and predict the genotypic and phenotypic ratios that will be observed by a cross between a (BW) genotype parent and a (WW) genotype parent. (blank) B W W BW WW W BW WW 3b. Write the proportions, percents, and ratios for the genotypes and phenotypes of this cross Genotype:Proportions = 0 or 0%BW = 2 or 50%WW = 2 or 50%Ratio: 1:1Phenotype:Proportions chickens = 0 or 0%Speckled chickens = 2 or 50%White chickens = 2 or 50%Ratio: 1:1 4a. Codominance One of the speckled offspring from the first cross is crossed with another speckled chicken. Please fill in the Punnett square and the genotypic and phenotypic ratios below for this cross. (blank) B W B BB BW W BW WW 4b. Write the proportions, percents, and ratios for the genotypes and phenotypes of this cross Genotype:Proportions = 1 or 25%BW = 2 or 50%WW = 1 or 25%Ratio: 1:2:1Phenotype:Proportions chickens = 1 or 25%Speckled chickens = 2 or 50%White chickens = 1 or 25%Ratio: 1:2:1 5a. Blood Type--Multiple Alleles Blood type in humans is a trait that is controlled by multiple alleles. The possible alleles that can be inherited are A, B, and O, but each person only inherits two alleles. Alleles A and B both produce antigens, but O produces no antigens. This means that a person who has an A or B allele or both will express that blood type. O is recessive to A and B so I like to use the lower case letter i to remind me that it is recessive. For example, Ai and AA = blood type A, Bi and BB = blood type B, and AB = blood type AB. Since O produces no antigens, it does not affect blood type when paired with A or B, but when a person inherits two O alleles (ii), they have blood type O.For a cross between an individual with the genotype (Ai) and an individual with the genotype (BB), please fill in the Punnett square and genotypic and phenotypic ratios below. (blank) A i B AB Bi B AB Bi 5b. Write the proportions, percents, and ratios for the genotypes and phenotypes of this cross Genotype:Proportions = 0 or 0%Bi = 2 or 50%AB = 2 or 50%AA = 0 or 0%BB = 0 or 0%Ratio: 1:1Phenotype:Proportions type A = 0 or 0%Blood type B = 2 or 50%Blood type AB = 2 or 50%Ratio: 1:1 6a. Blood Type: Multiple Alleles One of the offspring with blood type B from the cross above (in 5a) is crossed with a person with blood type AB. Please fill in the Punnett square and the genotypic and phenotypic ratios for this cross below. (blank) B i A AB Ai B BB Bi 6b. Write the proportions, percents, and ratios for the genotypes and phenotypes of this cross Genotype:Proportions = 1 or 25%Bi = 1 or 25%AB = 1 or 25%AA = 0 or 0%BB = 1 or 25%Ratio: 1:1:1:1Phenotype:Proportions type A = 1 or 25%Blood type B = 2 or 50%Blood type AB = 1 or 25%Ratio: 1:2:1