Problem set #1 Ashmore, Genetics 0350 Week 5 problem set Please do not distribute these problems outside of class 1. The following questions refer to the following pedigree, tracing a rare trait (#1)...

What is the most likely mode of inheritance?


Problem set #1 Ashmore, Genetics 0350 Week 5 problem set Please do not distribute these problems outside of class 1. The following questions refer to the following pedigree, tracing a rare trait (#1) and a common trait (#2) through the same family. (We are combining two different charts into one chart with this method. It may help you to redraw two separate charts to make who is affected/unaffected by each trait more clear. The inheritance of trait 1 doesn’t influence the inheritance of trait 2.) a. What is the most likely mode of inheritance for the rare trait, #1? b. What is the most likely mode of inheritance for the common trait, #2? c. What is the probability that the first offspring from a mating between individuals IV.2 and IV.7 will be affected by trait 1? (Don’t worry about trait 2.) Show all calculations below. d. What is the probability that the first offspring from a mating between individuals IV.2 and IV.7 will be affected by trait 2? (Don’t worry about trait 1.) Show all calculations below. e. Extra credit: III.3 marries III.7. What is the probability that all three of their children will be affected by both traits? Show all calculations below. Ashmore, Genetics 0350 2. Tribbles are little alien balls of fluff that can have long hair or short hair. When true- breeding long and true-breeding short haired tribbles are crossed, the offspring all have long hair. A second trait involves hair texture: wiry vs. straight. Offspring of pure-breeding wiry and straight parents are always wiry. A new hair trait pops up in one of your long-haired tribble stocks: grizzled (a very stiff hair phenotype). The hairs of this tribble are so thick and distorted that you can’t determine what the other traits are (long, short, straight, or wiry). You create a pure-breeding stock of grizzled tribbles. You do a series of crosses to determine whether the grizzled gene is a new gene, or a novel allele of one of the other two. All parents are true-breeding, and F2 offspring are the result of crosses of F1 siblings. Cross Parents: F1 F2 ratios 1 Short, straight x grizzled All grizzled 12 grizzled 3 long straight 1 short straight 2 Long, straight x grizzled All grizzled 3 grizzled 1 long straight 3 Long, wiry x grizzled All grizzled 3 grizzled 1 long, wiry 4 Short, wiry x grizzled All grizzled 12 grizzled 3 long, wiry 1 short, wiry A. Which of the original alleles (wiry vs, straight and long vs. short) are dominant? B. Is grizzled a new allele of the length (long vs. short) gene? What is your evidence? Explain what pattern of inheritance you see here: C. Is grizzled a new allele of the texture (wiry vs. straight) gene? What is your evidence? Explain what pattern of inheritance you see here: