Download Celebrity Genetics Details

Human Inheritance & Celebrity
Genetics Lab
Instructions
CLASS COPY – PLEASE RETURN THIS PACKET.
Introduction:
With an understanding of heredity and probability, biologists have learned about the genetics of many
human traits. For many of these traits, several pairs of genes are involved and the pattern of inheritance
is complex. For this activity we will assume that most of the traits we are studying are regulated by the
alleles of only one gene pair, with one allele from the father and one from the mother.
Why do people, even closely related people, look slightly different from each other? The reason for
these differences in phenotypes is the different combination of genes possessed by each individual.
To illustrate the tremendous variations in human inheritance, you will imagine that you have the
opportunity to marry and start a family with your favorite celebrity. 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
chromosome of each chromosome pair will be given, so these cells have only 23 single chromosomes
(haploid). In this way, you contribute half of the genotype for the child and your celebrity spouse will
contribute the other half. In doing this lab, you must assume that your dream celebrity has not had any
plastic surgery, and he or she was born with the traits that you’ve grown to love.
You’ll firsts look at your phenotypes for several facial features to narrow down your genotypes. Then
you’ll do the same for your celebrity partner. You will then use this information to create your child.
Objectives:
In this activity you will:
1. Determine your phenotype for several traits.
2. Determine (as far as possible) your genotype for the same traits.
3. Determine the frequency of dominant & recessive traits in the class.
4. Determine the phenotypes & genotypes of your dream celebrity.
5. Determine the phenotypes & genotypes of the child you would have with your dream celebrity.
6. Track the inheritance of genetic disorders in a pedigree.
7. Use a pedigree to predict family members’ genotype.
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Procedures:
Part I:
Phenotypes and genotypes of common traits
 You will determine your phenotype and try to determine your genotype for the traits listed in the
Part I Data Table.
 Remember, if you show a dominant trait, you may be homozygous or heterozygous for that trait.
Suppose, however, that one of your parents shows the recessive trait. In that case, the parent
would have passed on a gene for the recessive trait and you would be heterozygous for that trait.
If neither of your parents shows the recessive trait, you may not know whether you are
heterozygous or homozygous for that trait. In this case, put a blank (_) for the unknown allele.
 Since your parents are not here, only record your genotype as heterozygous if you display the
dominant trait and you know for sure one of them displays the recessive trait. If you show the
recessive trait, record it as the phenotype as well as the genotype, with two recessive alleles.
1.) Face Shape:
Round (AA, Aa)
Square (aa)
2.) Chin Size:
Prominent (BB, Bb)
Less Prominent (bb)
3.) Chin Shape: Only record this trait if chin size is prominent. The genotype bb prevents the
expression of this trait. If the chin is less prominent, put a dash (-----) through genotype
and phenotype on the data table.
Round (CC, Cc)
Square (cc)
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4.) Cleft Chin: Only flip coins for this trait if the chin size is prominent. The genotype bb
prevents the expression of this trait.
Present (DD, Dd)
Absent (dd)
5.) Skin Color (polygenic inheritance): To determine the color of skin or any other trait
controlled by more than 1 gene, you will need to flip the coin for each gene pair. Dominant
alleles represent color; recessive alleles represent little or no color. For example, if there
are 3 gene pairs…
6 dominant alleles (EEFFGG) = very dark brown
5 dominant alleles (EeFFGG) = medium - dark brown
4 dominant alleles (EeFfGG or eeFFGG) = light - medium brown
3 dominant alleles (EeFfGg or eeFfGG) = dark tan /light brown
2 dominant alleles (eeFfGg or eeffGG) = tan
1 dominant alleles (eeffGg) = light
0 dominant alleles (eeffgg) = very fair
6.) Hair Color: Determined by 4 gene pairs. (H, I, J, K)
8 dominant (HHIIJJKK) – black
7 dominant (HhIIJJKK) – very dark brown
6 dominant (HhIiJJKK) – dark brown
5 dominant (HhIiJjKK) – brown
4 dominant (HhIiJjKk) – light brown
3 dominant (hhIiJjKk) -brown mixed w/ blond
2 dominant(hhiiJjKk) - blond
1 dominant (hhiijjKk) - very light blond
0 dominant (hhiijjkk) - silvery white
7.) Red Color Tint in Hair: This trait is only visible if the hair color is light brown or lighter.
Epistasis results when the expression of the “red tint” gene is masked by darker hair color.
For Part I, if your hair is light brown or lighter, you can determine your genotype for this
trait, if it is darker, put a dash (------) through this section.
Dark red tint (L1L1)
Light red tint (L1L2)
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No red tint (L2L2)
8.) Hair Texture:
Curly (M1M1)
Wavy (M1M2)
Straight (M2M2)
9.) Widow’s Peak:
Present (NN,Nn)
Absent (nn)
10.) Eye Color:
Pigmented irises: If you have any color of eyes other than blue, you have pigment in the front layer
of the iris. This is dominant. If there is no pigment, your eyes will appear blue which is recessive.
Different color eyes result in different type and amount of pigment which relies on another gene.
OOPP – Black/Brown
Oopp – Green
OOPp – Dark Brown
ooPP - Gray Blue
oOPP – Brown with green flecks
ooPp – Dark Blue
OoPp – Brown
oopp – Light Blue
OOpp – Hazel
11.) Eye Distance:
Close (P1P1)
Average (P1P2)
12.) Eye Size:
Large (R1R1)
Medium (R1R2)
Small (R2R2)
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Far Apart (P2P2)
13.) Eye Shape:
Almond (SS, Ss)
Round (ss)
14.) Eye Slantedness:
Horizontal (TT,Tt)
Upward Slant (tt)
15.) Eye Lashes:
Long (UU,Uu)
Short (uu)
16.) Eyebrow Color:
Darker than hair color (V1V1)
Same as hair color (V1V2)
Lighter than hair color (V2V2)
17.) Eyebrow Thickness:
This describes thickness of eyebrows before plucking!
Thick (WW,Ww)
Fine (ww)
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18.) Eyebrow Length:
Not connected (XX,Xx)
Connected (xx)
19.) Mouth Size:
Long (Y1Y1)
Medium (Y1Y2)
Short (Y2Y2)
20.) Lip Thickness:
Thick (ZZ,Zz)
Thin (zz)
21.) Dimples:
Present (AA,Aa)
Absent (aa)
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22.) Nose Size:
Large (B1B1)
Medium (B1B2)
23.) Nose Shape:
Rounded (CC,Cc)
Pointed (cc)
24.) Nostril Shape:
Rounded (DD,Dd)
Pointed (dd)
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Small (B2B2)
25.) Earlobe Attachment:
Free (EE,Ee)
Attached (ee)
26.) Freckles on Cheeks:
Present (FF,Ff)
Absent (ff)
27.) Freckles on Forehead:
Present (GG,Gg)
Absent (gg)
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*** FOR PART I & II ONLY***
28.) Tongue Rolling:
A dominant allele, H, gives some people the ability to roll their tongues into a U
shape when it is extended. People with the recessive alleles, hh, cannot roll their
tongues. Check to see if you can roll your tongue.
29.) PTC Tasting:
Individuals who can taste bitter chemical phenylthiocarbamide, PTC, have at least one dominant
allele, I. Those with the recessive genotype, ii, cannot taste it. Take a piece of PTC paper from the
supply station. Place the untouched end to your tongue to find out if it tastes bitter to you. Put the
paper in the trash, and record your phenotype and genotype in Table 1.
30.) Bent Pinky:
A dominant allele, J, results in the end joint of the little finger of each hand
bending inward. Straight little fingers are a result of the recessive genotype
jj. Place your hands on a flat surface, palms down, and relax. Check to see
if the first joints of your little fingers are bent in or straight. If you still
have trouble, hold your hands together as if you are covering your face. If
the tips of the pinkies point away from one another, the pinkies are bent.
Record your phenotype and genotype in Table 1.
31.) Hairy fingers:
Individuals who have hair on the middle joints of their fingers (mid-digit hair) have at
least one dominant allele, K. Those with two recessive alleles, kk, do not have hair on
that joint. Check to see if you have hair on the middle joints of your fingers. Look for
hair only on the finger shown by the white arrow below. Record your phenotype and
genotype in Table 1.
32.) Hitchhiker’s thumb:
A dominant allele, L, results in the ability to bend one's thumb tip
backwards more than 30 degrees (hitchhiker's thumb). Stick your
thumb up to see if it bends back or if it is straight. Record your
phenotype and genotype in Table 1.
33.) Long palmer muscle:
Make a fist and look at the inside of your write while moving your
fist back & forth. If you see only two tendons, you have the
dominant trait, M_. If you see three, you are recessive, mm.
34.) Color vision
Color blindness is a sex-linked recessive trait, so when writing your genotype, you must include
your sex chromosomes. (ex. XNY, XNXn, etc.) Are you red green colorblind or do you have
normal color vision? If you are female and your dad is colorblind, then you are heterozygous.
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

Part III:
Determine your favorite celebrity’s phenotypes and genotypes for traits 1-27, and record them in
Table 3.
Part IV:
Determine the phenotypes & genotypes of the child you would have with your dream celebrity.
Record your results in Table 4. Draw a picture of your baby when you finish.
 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
 Name the child (first and middle name; last name can be father’s last name, mother’s last name
or hyphenated last name).
 Record your genotype & your dream celebrity’s genotype for face shape (from Tables 1 & 3) in
the spot for the parental cross above Punnett square 1 on p. 15. If the genotype is unknown,
assume it is heterozygous.
 Determine the child’s face shape by completing the Punnett square. Each square of the Punnett
square is assigned a number. Roll a die to see which genotype your child will have. If you roll a
5 or a 6, then reroll.
 Circle the genotype on the Punnett square that corresponds to the number you roll.
 On the Table 4, check off and record your child’s genotype and phenotype.
 Repeat this procedure for all 27 traits.
 Some traits follow special conditions, which are explained as they come up.
 When you have completed determining your child’s phenotype, draw a portrait of him or her.
Part V:

Read about pedigrees on pages 309 – 311 in your text and complete the genotypes and questions for
the pedigrees on your answer sheet.
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Date:
Name:_______________________________________ Period: ______
Human Inheritance Lab
Answer Sheet (100 points)
Part I: My Traits
#
Trait
A
Face Shape
1
B
Chin Size
2
C
Chin Shape
3
D
Cleft Chin
4
EFG Skin Color
5
HIJK Hair Color
6
L
Red Tints
7
M
Hair Type
8
N
Widow’s Peak
9
OP Eye Color
10
Q
Eye Distance
11
R
Eye Size
12
S
Eye Shape
13
T
Eye Slantedness
14
U
Eyelash Length
15
V
Eyebrow Color
16
W
Eyebrow Thickness
17
X
Eyebrow Length
18
Y
Mouth Size
19
Z
Lip Thickness
20
A
Dimples
21
B
Nose Size
22
C
Nose Shape
23
D
Nostril Shape
24
E
Earlobe Attachment
25
F
Freckles on Cheeks
26
Freckles on Forehead
G
27
H
Tongue Rolling
28
I
PTC Tasting
29
J
Bent Pinky
30
K
Hairy Fingers
31
L
Hitchhiker’s Thumb
32
M
Palmer Muscle
33
N
Color vision
34
Phenotype
Genotype
If you have the recessive phenotype, do you know your genotype?
When is the only time you determine your genotype if you are dominant for a trait? Explain.
Why can you never say for sure that you are homozygous dominant for a trait?
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Celebrity Genetics
Part III: My Mate’s Traits – My dream celebrity is __________________________.
#
1
A
Trait
Face Shape
2
B
Chin Size
3
C
Chin Shape
4
D
Cleft Chin
5
EFG
Skin Color
6
HIJK
Hair Color
7
L
Red Tints
8
M
Hair Type
9
N
Widow’s Peak
10
OP
Eye Color
11
Q
Eye Distance
12
R
Eye Size
13
S
Eye Shape
14
T
Eye Slantedness
15
U
Eyelash Length
16
V
Eyebrow Color
17
W
Eyebrow Thickness
18
X
Eyebrow Length
19
Y
Mouth Size
20
Z
Lip Thickness
21
A
Dimples
22
B
Nose Size
23
C
Nose Shape
24
D
Nostril Shape
25
E
Earlobe Attachment
26
F
Freckles on Cheeks
27
G
Freckles on Forehead
Phenotype
12
Genotype
Part IV: Our Baby’s Traits
Parents _____________________________________ and ____________________________________
Child’s Gender____________________ Child’s Name________________________________________
#
Trait
Genotype
Phenotype
Homozygous
Homozygous
Heterozygous
Dominant
Recessive
A
Face Shape



1
B
Chin Size



2
C
Chin
Shape



3
D
Cleft Chin



4
EFG Skin Color



5



6 HIJK Hair Color
L
Red Tints



7
M
Hair Type



8
Widow’s
N



9
Peak



10 OP Eye Color
Q
Eye Distance 


11
R
Eye Size



12
S
Eye Shape



13
Eye
T



14
Slantedness
Eyelash
U



15
Length
Eyebrow
V



16
Color
Eyebrow
W



17
Thickness
Eyebrow
X



18
Length
Y
Mouth Size



19
Lip
Z



20
Thickness
A
Dimples



21
B
Nose Size



22
C
Nose Shape



23
D
Nostril Shape 


24
Earlobe
E



25
Attachment
Freckles on
F



26
Cheeks
27
G
Freckles on
Forehead



13
1.
_________ x _________
1
2
3
4
5.
______________ x ______________
 For each letter that you are heterozygous for,
flip a coin.
 The result will represent the allele you give
to your offspring.
 Heads = dominant & tails = recessive.
 Repeat this for your dream celebrity to
determine which alleles you’ll each give
your child.
6.
2.
______________ x ______________
 For each letter that you are heterozygous for,
flip a coin.
 The result will represent the allele you give
to your offspring.
 Heads = dominant & tails = recessive.
 Repeat this for your dream celebrity to
determine which alleles you’ll each give
your child.
_________ x _________
1
2
3
4
*7.
*3.
1
2
3
4
_________ x _________
1
2
3
4
8.
4.
_________ x _________
_________ x _________
1
2
3
4
_________ x _________
1
2
3
4
14
9.
_________ x _________
13.
1
2
3
10.
2
3
4
_____________ x _____________
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
14.
15.
_________ x _________
1
3
12.
1
4
Roll 3 times & add up the total of the 3 rolls.
11.
_________ x _________
_________ x _________
1
2
3
4
_________ x _________
1
2
3
4
2
4
16.
_________ x _________
_________ x _________
1
2
1
2
3
4
3
4
15
17.
18.
19.
20.
_________ x _________
21.
_________ x _________
1
2
1
2
3
4
3
4
_________ x _________
22.
_________ x _________
1
2
1
2
3
4
3
4
_________ x _________
23.
_________ x _________
1
2
1
2
3
4
3
4
_________ x _________
24.
_________ x _________
1
2
1
2
3
4
3
4
16
25.
26.
_________ x _________
27.
_________ x _________
1
2
1
2
3
4
3
4
_________ x _________
1
2
3
4
Child’s Portrait
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Conclusions:
1. What percentage does each parent contribute to a child’s genotype? (In each Punnett square,
what percentage of the offspring’s genotype was from the mom & what percentage was from the
dad?)
2. List examples of traits (from your baby’s data) table where each of the following was shown:
a. Dominant trait
b. Recessive trait
c. Incomplete dominance
d. Polygenic inheritance (HINT: Refer to instruction packet.)
e. Epistasis (HINT: Refer to instruction packet.)
Part V: Family Traits
Tracing Genes in a Family
The pedigree below tracks the history of albinism in a family (as shown by shapes that have been filled
in). Albinism is an autosomal recessive disorder. Use “p” to represent the allele for albinism and “P” to
represent the allele for normal pigmentation. Write the genotype below each individual in the pedigree.
If the complete genotype cannot be determined, record “P__.”
I.
1
2
3
4
II.
1
2
5
6
7
III.
1
2
3
4
5
6
18
7
8
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The pedigree below shows the inheritance of sickle cell anemia (ss) in a family. Fill in the genotypes of
the individuals in the family in Table 2.
Generation
Individual
I
1
2
3
4
1
2
3
4
1
2
3
4
5
6
7
8
9
1
2
II
III
IV
Genotype
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