Pedigree Worksheet Template (Page 2 of 2) in pdf

Name: ___________________________________

Date: _____ Period: _____

B. Determining the pattern of inheritance and assigning genotypes. (35 points)

When working through a pedigree, the first thing you need to do is figure out which characteristic is dominant-the

shaded one or the open one. Then you need to choose a letter (let’s use A) and begin assigning genotypes. Remember that

recessive individuals are always homozygous, so assign their genotypes first. Then go back and look at all of the dominant

individuals. For some, you will only be able to determine one allele of the genotype, so just write the one capital allele followed

by a dash (A- ).

Fur Color in Mice

1. Which characteristic is dominant?

___________________.

Which characteristic is recessive?

___________________.

2. Determine the genotypes of all individuals.

You will have three (A-)s. Write your

genotypes beneath each individual.

= white female

= black female

= white male

= black male

C. Create Your Own Pedigree (35 points)

In the space below, use colored pencils to create a pedigree with the following information. Follow the guidelines for a

pedigree when creating this one.

Ray and Elaine were married in 1970. They both had normal vision. They had 2 daughters and then a son.

Both daughters, Alicia and Candace, had normal vision and never had any children of their own. The son, Mike, was

colorblind. The son married Beth who also had normal vision and they had 2 children of their own, first Greg then

Victoria. Victoria was colorblind, but Greg was not. Colorblindness is a sex-linked recessive trait.

Do not forget what shapes are male and female. Place the names and genotypes of the people under their shape.

Color your individuals the following:

Red- for colorblindness

White- for regular vision

Blue- for individuals with regular vision but are carriers

Green- unknown genotype

Pedigree Worksheet Template Page 2