Reference no: EM133270594

Assignment - Punnett Square Practice

Answer the following questions and show your work!

Q1. In rabbits, black fur is dominant to white fur. You capture two black rabbits, one male and one female, and determine each genotype. The male is homozygous for the black fur allele, and the female is heterozygous for the black fur allele. If these two individuals had offspring, what would be the ratio of the F1 generation genotypes? What would be the ratio of the F1 phenotype?

Q2. The leaves of the interior live oak (Quercus wislizeni) can have a margin that is either toothed or smooth. You cross-pollinate an individual with a toothed margin with one with a smooth margin. In the resulting F1 generation, half of the individuals have a toothed margin, and the other half has a smooth margin. You cross-pollinate two individuals from the F1 generation with toothed margins, and the F2 generation results in 75% toothed and 25% smooth margin. What were the genotypes for the parental generation?

Q3. Weevil snout length is coded by a single gene, with the dominant allele resulting in a long snot, and the recessive allele resulting in a short snout. If two short-snouted weevils reproduced, what would be the genotypes and phenotypes of the F1 generation? F2 generation?

Q4. You cross a pea plant that produces yellow, wrinkled seeds, with a pea plant that produces green, smooth seeds. All of the F1 generation seeds are green and smooth. What would be the F2 genotype and phenotype ratios?

Q5. Dogs with merle coats have a risk of producing deaf offspring if they interbreed. However, if a dog with a roan coat reproduces with a dog with a merle coat, there is no risk of deafness in offspring, and the offspring usually have a roan coat. If two siblings reproduce, what percent of the resulting offspring would potentially be deaf? What would be the frequency of coat patterns in this generation?

Q6. Diabetes has been found to be inherited, in some cases, through a recessive allele. What is the chance that a heterozygous father and a diabetic mother would have a diabetic offspring?

Q7. In humans, alleles that express blood type A and blood type B are codominant. If your mother is homozygous for blood type A and your father has blood type AB, what is the chance that you will have blood type A? Blood type B? Blood type AB?

Q8. Your grandmother was colorblind, but your grandfather was not. They had four children, three girls (including your mother), and one boy. None of the girls were colorblind, but the boy was colorblind. Your father is not colorblind, your brother is colorblind, and your sister is not colorblind. What type of inheritance is this gene? If you reproduce with someone that is homozygous for normal color vision, what is the chance that your offspring will be colorblind if you are male? Female?

Q9. Most fruit flies (Drosophila melanogaster) have red eyes, but you notice that some have white eyes. You capture both male and female white-eyed fruit flies and have them reproduce. The F1 generation phenotype results in 100% white eyes. You then have the F1 generation reproduce with a male fruit fly with red eyes. In the new F1 generation phenotype, you notice that the female fruit flies have red eyes and the male fruit flies have white eyes. What would be the ratio of red and white eyes in the F2 generation for both male and female fruit flies? If you then cross-fertilized male and female fruit flies with red eyes from the F2 generation, what would be the resulting genotype and phenotype frequency in the F3 generation?

Q10. In one population of red sea urchins, individuals have short, thick spines. In a second population of red sea urchins, you notice that the spines are long and thin. You take one from each population back into the lab and cross-fertilize. In the next generation, you find that 100% of individuals have long, thick spines. What ratios would you expect to find in the F2 generation for spine thickness and spine length?