Reference no: EM133477216

Background: This week we are learning about the structure of DNA, genetic inheritance patterns, and the major processes of replication, transcription, and translation that regulate gene expression. This activity will help to focus on the week's learning objectives in order to prepare for this week's quiz, application assignment and reflection journal.

Learning Objective 5a. Analyze the genotypes and phenotypes of offspring from genetic crosses between dominant and recessive parents.

First, review the material on genetic terminology and Mendel's experiments with peas in Sections 8.1 and 8.2 of the textbook and review the Week 5 Learning Objectives pdf. In those sections, you studied examples of monohybrid crosses displaying complete dominance in plants. Let's now try to walk through an example of monohybrid crosses displaying complete dominance in animals. Mating of parents and F1's works a bit different in animals (for example, you cannot "self-fertilize" most animals, but you can mate male and female animals with the same genotypes and get the same results). Hopefully you will recognize some similar patterns as you work through this example involving hair texture in dogs.

So, a hair texture gene exists in dogs with two alleles, the dominant allele (W) produces wiry hair and the recessive allele (w) produces smooth hair. Respond to the following questions that walk you through a monohybrid cross.

Question 1. Using the information above, what would be the genotype of a true-breeding smooth-haired dog?

Question 2. Using the information above, what would be the genotype of a true-breeding wiry-haired dog?

Question 3. What would be the genotype of the F1 dogs produced from a mating between a true-breeding smooth-haired female dog and a true-breeding wiry-haired male dog?

Question 4. What would be the phenotype of the F1 dogs produced from a mating between a true-breeding smooth-haired female dog and a true-breeding wiry-haired male dog?

Question 5. The Punnett Square table below providing male and female parent gametes and F2 genotypes and their probabilities (as fractions) expected for the mating of an F1 female dog with an F1 male dog.

Question 6. List the different F2 phenotypes and their ratio that would result from the mating in question 5 above.