BAG O’ GENES
CONTENTS of each bag:
1. 8 popsicle sticks –
Each popsicle stick represents the haploid, or single chromosome of a pair.
Female - 4 egg cells
Male – 4 sperm cells
Alleles:
Female – eggs – 2 dominant alleles and 2 recessive alleles
Male – sperm – 2 dominant alleles and 2 recessive alleles
D = dominant and R = recessive
2. Worksheets: 2 pages of facial traits
3. Worksheets: Human Face outlines
4. Worksheet: Wrap it Up! - questions
PART ONE – SINGLE ALLELIC TRAITS
Human facial features have been analyzed from the shape of the head to
presence of dimples.
These facial features are visible to us and are the expression of our genes. These
are called phenotypes.
In this activity, these facial features are determined by a single gene with two
forms (alleles). These dominant and recessive alleles are inherited from an
individual’s parents. Allelic combinations are our genotype.
ACTIVITY – work in pairs or threes
In this activity, you will build a family tree. You will start with using the genes on
sticks to generate genotypes and then draw the facial features (phenotypes) of
the Mom and Dad.
Then you will use these genotypes and punnet squares to demonstrate your
knowledge of the Mendelian laws of inheritance to describe their offspring.
ACTIVITY: BUILDING A FAMILY TREE –
Step 1: MEET THE PARENTS: What are the genotypes of the parents?
To build the genotypes, you will use the popsicle sticks. Example: Shape of Head
1. Turn the 8 sticks over so that you can only read “sperm” and “egg”
2. Select one sperm cell and one egg cell.
3. Flip these two popsicle sticks over.
a. Keep the stick flipped over so you can read: the male allele (D or R)
b. Keep the stick flipped over so you can read: the female allele (D or R)
4. Go to the worksheet and decode using the lettering system on the
worksheet.
Eg. Shape of Face – ROUND (RR) and (Rr) or SQUARE (rr)
If I got a sperm cell popsicle stick “D”
and an egg cell popsicle stick “R”,
the genotype is Rr
the phenotype is Round
This is a heterozyogote! (Huhh, A what kinda goat?)
5. Use the work sheet to keep track. On the worksheet showing each facial
feature and the different geno/pheno-types, mark the square that matches
your genotype using “F” for female and “M” for male.
6. CONTINUE FOR EACH HUMAN FACIAL TRAIT (from shape of head to
dimples)!
I wonder, can you guess your genotypes?
7. Using the human face outlines, draw a representation of the Mom and the
Dad! Give them names! If you want to decide on hair and eye colour, see
page 3
STEP TWO:
Using the parents’ genotypes, what will their children look like? Let’s imagine
that these parents have 4 children.
8. Do punnet squares, for a SELECTION of facial traits do a hybrid cross.
Record the data here: # that are dominant DD, # heterozygous (Dd), and #
recessive (dd)
Record the name of the trait
# Dominant
(DD)
# Heterozygous
(Dd)
# Recessive
(dd)
JUST FOR FUN!! – what is your genotype? Hair and Eye Colour.
Ever wondered about your hair and eye colours? These are ”polygenic
traits”. At least two genes determine the colour. Genes code for proteins
in pigment cells. As the quantity of proteins varies, so too does colour
If the
The hair
genotype is: colour is
The eye colour is
AABB
AABd
AAbb
AaBB
Aabb
AaBd
aaBd
aaBd
Aabb
Dark brown
Dark brown
Brown
Brown w green flecks
Brown
Grey
Green
Dark blue
Light blue
Black
Black
Red
Brown
Regular blonde
Brown
Dark blonde
Regular blonde
Pale yellow
blond
Your Hair Your eyes
(genotyp (genotype
e)