STUDENT WORKSHEET

STUDENT WORKSHEET
The Genetics of Parenthood Data Sheet
Parents _____________________________ and ___________________________________
Child's gender _____
Child's name _________________________________
Fill in data table as you determine each trait described in the Guidebook. Do not simply flip the coin for all
traits before reading the guide, because some traits have special instructions. Believe it or not, it will make
your life easier if you follow directions. In the last column, combine the information and draw what that
section of the child's face would look like.
CHILD'S
CHILD'S
ALLELE FROM ALLELE FROM
CHILD'S
#
TRAIT
PHENOTYPE
PHENOTYPE
MOM
DAD
GENOTYPE
(written)
(drawn)
1
Face Shape
A a
A a
2
Freckles
F f
F f
3
Dimples
D d
D d
4
Cleft Chin
C c
C c
5
Skin Color
E e F f G g
E e F f G g
Hair Color
H h I i
J j K k
H h I i
J j K k
7
Red Tints
L1 L2
L1 L2
8
Hair Type
M m
M m
9
Widow's Peak
O o
O o
10
Eye Color
P p Q q
P p Q q
11
Eye Distance
R r
R r
12
Eye Size
S s
S s
13
Eye Shape
T t
T t
14
Eye
Slantedness
U u
U u
15
Eye Lashes
V v
V v
W w
W w
X x
X x
6
16
17
Eyebrow
Color
Eyebrow
Thickness
18
Nose Size
Y y
Y y
19
Mouth Size
Z z
Z z
20
Lip Thickness
T t
T t
21
Ear Size
L l
L l
face & chin
hair
eye & eyelashes
eyebrow
mouth
STUDENT REFERENCE
The Genetics of Parenthood Guidebook
Why do people, even closely related people, look slightly different from each other? The reason for these
differences in physical characteristics (called phenotype) is the different combination of genes possessed by
each individual.
To illustrate the tremendous variety possible when you begin to combine genes, you and a classmate will
establish the genotypes for a potential offspring. Your baby will receive a random combination of genes that
each of you, as genetic parents, will contribute. Each normal human being has 46 chromosomes (23 pairs diploid) in each body cell. In forming the gametes (egg or sperm), one of each chromosome pair will be given,
so these cells have only 23 single chromosomes (haploid). In this way, you contribute half of the genetic
information (genotype) for the child; your partner will contribute the other half.
Because we don't know your real genotype, we'll assume that you and your partner are heterozygous for
every facial trait. Which one of the two available alleles you contribute to your baby is random, like flipping a
coin. In this lab, there are 36 gene pairs and 30 traits, but in reality there are thousands of different gene pairs,
and so there are millions of possible gene combinations!
Procedures
Record all your work on each parent's data sheet.

First, determine your baby's gender. Remember, this is determined entirely by the father. The
mother always contributes an X chromosome to the child.
Heads = X chromosome, so the child is a GIRL
Tails = Y chromosome, so the child is a BOY
Fill in the results on your data sheet.

Name the child (first and middle name; last name should be the father's last name).
Determine the child's facial characteristics by having each parent flip a coin.
Heads = child will inherit the first allele (i.e. B or N1) in a pair
Tails = child will inherit the second allele (i.e. b or N2) in a pair
On the data sheet, circle the allele that the parent will pass on to the child and write the child's
genotype.



Using the information in this guide, look up and record the child's phenotype and draw that
section of the face where indicated on the data sheet.
Some traits follow special conditions, which are explained in the guide.
When the data sheet is completed, draw your child's portrait as he/she would look as a
teenager. You must include the traits as determined by the coin tossing. Write your child's full
name on the portrait.
(HOMOZYGOUS)
DOMINANT – both
heads
(HETEROZYGOUS)
HYBRID- 1 heads; 1
tails
(HOMOZYGOUS)
RECESSIVE – both tails
Round (RR)
Round (Rr)
Square (rr)
Present (FF)
Present (Ff)
Absent (ff)
Present (DD)
Present (Dd)
Absent (dd)
Present (CC)
Present (cc)
Absent (cc)
SKIN COLOR
6 Dominant Alleles =
Black (EE,FF,GG)
5 Dominant Alleles =
Very Dark Brown
4 Dominant Alleles =
Dark Brown
3 Dominant Alleles =
Medium Brown
2 Dominant Alleles =
Light Brown
1 Dominant Alleles =
Light Tan
0 Dominant Alleles =
White (ee,ff,gg)
HAIR COLOR
8 Dominant Alleles =
Black (HH,II,JJ,KK)
7 Dominant Alleles =
Very Dark Brown
6 Dominant Alleles =
Dark Brown
5 Dominant Alleles =
Brown
4 Dominant Alleles =
Light Brown
3 Dominant Alleles =
Brown Blonde Mix
2 Dominant Alleles =
Blonde
1 Dominant Alleles =
Very Light Blonde
0 Dominant Alleles =
Silvery White
(hh,ii,jj,kk)
TRAITS
FACE SHAPE
FRECKLES
DIMPLES
CLEFT CHIN
** RED COLOR
TINTS IN HAIR
Dark Red Tint (L1L1)
Light Red Tint (L1L2)
No Red Tint (L1L2)
Curly (MM)
Wavy (Mm)
Straight (mm)
Present (OO)
Black (PPQQ)
Dark Brown (PPQq)
Brown w/Green Tints
(PpQQ)
Present (Oo)
Absent (oo)
Brown (PpQq)
Violet (PPqq)
Gray Blue (Ppqq)
Green (ppQQ)
Dark Blue (ppQq)
Light Blue (ppqq)
Close (RR)
Average (Rr)
Far Apart (rr)
Large (SS)
Medium (Ss)
Small (ss)
Almond (TT)
Almond (Tt)
Round (tt)
Horizontal (UU)
Horizontal (Uu)
Upward Slant (uu)
Long (VV)
Long (Vv)
Short (vv)
HAIR TYPE
WIDOW’S PEAK
EYE COLOR
EYE DISTANCE
EYE SIZE
EYE SHAPE
EYE
SLANTEDNESS
EYE LASHES
EYEBROW COLOR
Darker Than Hair Color
(WW)
Same As Hair (Ww)
Lighter Than Hair (ww)
Bushy (XX)
Bushy (Xx)
Fine (xx)
Large (YY)
Medium (Yy)
Small (yy)
Long (ZZ)
Medium (Zz)
Short (zz)
Thick (TT)
Thick (Tt)
Thin (tt)
Large (LL)
Medium (Ll)
Small (ll)
EYEBROW
THICKNESS
NOSE SIZE
MOUTH SIZE
LIP THICKNESS
EAR SIZE
Problem
How are traits inherited?
Pre-Lab Discussion
Read the entire investigation. Then, work with a partner to answer the following questions.
1. What does a single side of a double-sided coin or disk represent?
Each single side of a coin or disk represents one of two possible alleles.
2. What is the probability, in percent, that a single coin toss will result in heads? In tails?
The probability that a single coin toss will result in either heads or tails is 50 percent.
are the result of the combination of two alleles, or an allele pair.
3. Why is a coin toss a good way to represent allele combinations that occur in nature?
The combination of alleles in nature occurs by chance, as does the result of
a coin toss.
4. For the traits explored in this lab, do all heterozygous pairs of alleles produce an intermediate phenotype?
No; for some
of the traits listed, heterozygous pairs produce only the dominant phenotype.
5. Can you accurately determine an organism’s genotype by observing its phenotype? Explain your answer.
Although knowing an organism’s genotype would allow one to predict its phenotype, some phenotypic traits
can
Analysis and Conclusions
1. Inferring. What are the possible genotypes of the parents of an offspring who has wavy (Hh) hair?
HH
2. Predicting. Would you predict that another pair of students in your class would have an offspring
genetically identical to yours? Support your answer.
Because the genotype of each trait is determined by chance, and because there are so many traits considered,
the probability of two genetically identical offspring within a single class is highly unlikely.
3. Drawing Conclusions. Do you think anyone in your class has all the same genetic traits that you have?
Explain your answer.
No. Each person has a unique combination of many genetic traits passed on to them by their parents.
(Identical
twins, however, do share all of their genetic traits.)
4. Comparing and Contrasting. How is this coin-toss model similar to the way in which traits are inherited in
living things? How is the model different? nations