Name: Shania Predicting Offspring: Incomplete Dominance and Codominance 1) A cross between a blue bird & a white bird produces offspring that are silver. The color of the birds is determined by just two different versions (alleles) of one gene. a) What type of dominance is this? b) What are the genotypes of the parent birds in the original cross? Make sure to define the letters you use to represent the different alleles. c) What is the genotype of the silver offspring? d) Use a Punnett Square to predict the genotypic and phenotypic probabilities of offspring produced by two silver birds: 2) A cross between a black cat & a tan cat produces a tabby pattern (black & tan fur together). a) What pattern of inheritance does this illustrate (what type of dominance)? b) Use a Punnett Square to predict what percent of kittens would have tan fur if a tabby cat is crossed with a black cat (make sure to define the letters you use to represent the different alleles): 3) Blood type is an example of a codominant trait in humans: Group A Group B Group AB Group O Genes Blood Type AA A Red blood AO А A B AB ееll type AB AB BO B BB B In 1968, a couple accused a hospital of switching their baby with another. DNA fingerprinting did not 00 0 exist at this time so the hospital traced the blood types of the family in order to determine if a mistake was made. The mother had type A blood, the father had type AB blood, and the baby had type O blood. Use the Punnett Square to defend your answer to the following question: Did the hospital make a mistake and switch the baby? Shania 1 1. Punnett Square Practice Problems Two Alien Bugs are heterozygous for nose color and have blue noses. 1. What genotype do they both have for nose color? 1. Set up a Punnett Squate to predict what their children could look like What are the probabilities of every genotype and phenotype? one horn 2. A In the land of Purple People Faters one-horn is dominant (Hi and no home is raressive lhi Draw a Dunnon Square showing the cross of a purple people eater that is heterozygous for horns (Hh) with a purple people eater that is homozygous recessive and does not have horns (hh): H h = horn genotypes could C. What percent of their offspring will have horns? What percent will have no horns? Explain your response: 3. In seals, the gene for the length of the whiskers has two alleles, long and short. If a homozygous long-whiskered seal mates with a homozygous short-whiskered seal, and all of their offspring have long whiskers, what would you conclude about which alleie is dominant and why? What would the genotype of all of their offspring be, and why? 4. A green-leafed plant is crossed with a plant with yellow-striped leaves (the parent generation). The cross produces 185 green-leafed plants (the second generation). Two of these plant offspring are then crossed to create a third generation of plants, of which there are exactly 100. Summarize the genotypes and phenotypes of the offspring that would be seen in this third generation, and specify how many you would expect to see of each: 5. A scientist named Gregor Mendel found that crossing wrinkle-seeded pea plants with round-seeded pea plants produced only round-seeded plants. What genotypic & phenotypic ratios can be expected from a cross of a wrinkle-seeded plant & a plant heterozygous for seed appearance?