Assignment: Using a Pedigree Diagram to Determine the Mode of Inheritance (25
points)
The pedigree diagram below represents the inheritance of a genetic condition in an extended
family. The shaded symbols represent people who express the trait. It is unknown whether this
trait is dominant, recessive, or x-linked recessive.
Study the pattern of phenotypes shown in this family and answer the Analysis questions below.
Hint: It may be helpful to copy the pedigree diagram into your notes and write the possible
genotypes of each individual next to the symbol. Use the letter N/n to represent the trait.
Analysis Questions
1. What is the probable mode of inheritance for this trait (dominant, recessive, or x-linked
recessive)? 5 points
2. What is the genotype of person 1? Explain your answer. 5 points
3. What is the genotype of person 10? Explain your answer. 5 points
4. If individuals 3 and 4 have more children, is it possible for them to show the trait? Explain
your answer. 5 points
© KC Distance Learning
5. If person 13 has children with someone who has the condition, is it possible that their
children will not inherit the condition? 5 points
Please post your completed worksheet to the Using a Pedigree Diagram to Determine the
Mode of Inheritance Assignment link for grading.
© KC Distance Learning