Download Pedigree Assignment - It Runs in the Family (recovered) Introduction

Pedigree Assignment - It Runs in the Family (recovered)
Introduction:
Many human traits have two forms –dominant and recessive. Dominant genes are represented
with a capital letter, while recessive genes are represented with the lower case version of the
same letter. Examples of single inheritance traits include the ability to roll one’s tongue, the
shape of the hairline, and earlobe attachment.
The term phenotype refers to an individual’s physical appearance, while genotype refers to his or
her genetic makeup. It is not always possible to figure out a person’s genotype from seeing his or
her phenotype.
A pedigree is a diagram that shows how the phenotype of a genetic trait appears in a family from
one generation to the next.
Purpose:
To collect family data of a single inheritance trait and to make a pedigree.
Procedure:
Pick a trait from the list of dominant and recessive traits from the back of a previous handout
(examples: cleft chin vs. smooth chin, freckles vs. none, widow’s peak vs. straight hairline, etc.).
Make a diagram that represents your family that looks something like the following:
Write the phenotype for each family member under their symbol. Lightly shade in the boxes of
the family members that show the dominant trait with a pencil crayon (for example, brown eyes
if you chose eye colour, leaving the blue-eyed family members blank). Refer to Mrs. ten Hove’s
eye colour example:
Using the phenotypes of each family member, try to identify the possible genotypes of all family
members and write them in their box. Some may have 2 options (then write “BB or Bb” for
example). Refer to the example:
Make a mini-poster that neatly and attractively displays your family pedigree.
Sample: