Non-Mendelian Inheritance

Anaylzing Pedigrees

A pedigree is a chart that is used to explain patterns of inheritance within a family or close gene pool.  It is basically a family tree showing a specific trait that runs in the family that may or may not by passed on from generation to generation.  Individuals in a family are recognized by shapes, shading, and connecting with lines.  A normal male not expressing the trait is characterized by a non-shaded square. A male expressing the trait is shown by a shaded square.  In fact, anyone expressing the trait is shaded.

A pedigree is a chart that is helpful in explaining patterns of inheritance within a family. In order to create a pedigree, the gene pool must be closed. You can think of a pedigree like a family tree that shows the traits that are passed from generation to generation.

In a pedigree, individuals in a family are recognized by shapes, shading, and connected with lines. In the pedigrees, a normal male not expressing the trait is characterized by a non-shaded square. A male expressing the trait is expressed as a non-shaded square. Females follow the same pattern but use circles instead of squares.

This activity is available below or in a printable version.

Part I

Analyze the pedigree by answering the questions in the blank space provided on the Anaylzing Pedigrees Template.

1. What is the oldest member of this family?
2. What is the youngest member of this family?
3. What is the youngest female in this family?
4. Explain how you know 10 and 11 are both affected by sickle cell?
5. Who are members of the family that have no children?
6. How many children did 8 and 9 have?

Part II

Analyze the pedigree by answering the questions in the blank space provided on the Anaylzing Pedigrees Template.

7. Number the generations and each person on the pedigree
8. Fill out the following table by determining the pedigree of each of the listed individuals.

Person	Genotype
3
4
5
6
7
8
9
10
11

9. What is the probability that the new baby will have webbed feet?

Part III

Read the scenario and draw a corresponding pedigree in the blank space Anaylzing Pedigrees Template.

Couple A has a son and daughter with normal skin pigmentation and another son who is albino. Couple B has one son and two daughters with normal skin pigmentation. The daughter from the Couple A has three children with the son from the Couple B. Their son and one daughter have albinism, and their other daughter has normal pigmentation.

Once you have completed the Analyzing Pedigrees Template, please submit your work to the drop box.