Download Create a Baby Lab

Create a Baby Lab
Investigating Inherited Traits
Introduction
Heredity is the passing on of traits from parent to offspring. The genetic
makeup of an individual is known as its genotype. The physical
characteristics of an individual, which are the result of its genotype and
its environment, are known as its phenotype. Some alleles are expressed
only when the genotype is homozygous. These alleles are said to
produce recessive phenotypes. Alleles that are expressed whether the
genotype is homozygous or heterozygous produce dominant
phenotypes. An allele that codes for a dominant trait is represented by a
capital letter, while an allele that codes for a recessive trait is
represented by a lowercase letter. Sometimes when the genotype is
heterozygous, neither the dominant
nor the recessive phenotype occurs. In this situation, called incomplete
dominance, an intermediate phenotype is produced.
In humans, the sex of an individual is determined by the particular
combination of two chromosomes called the sex chromosomes.
Individuals who have two X chromosomes (XX) are females, whereas
those who have an X and a Y chromosome (XY) are males. In this
investigation, you will observe how the results of different allele
combinations produce certain traits.
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?ach
2. What is the probability, in percents, that a single coin toss will result
in heads? In tails?
3. Why is a coin toss a good way to represent allele combinations that
occur in nature?
4. For the traits explored in this lab, do all heterozygous pairs of alleles
produce an intermediate phenotype?
5. Can you accurately determine an organism’s genotype by
observing its phenotype? Explain your answer.
Create-A-Baby Procedure
1. Decide who will be the dad and who will be the mom by flipping the
penny once. Heads you are the dad and tails you are the mom.
2. The dad then flips the coin to see what gender the child will be.
Heads, the dad will pass on his Y chromosome and tails, he will pass on
his X chromosome. Place this in the chart as your first trait.
3. Have your partner tell you what trait you show for each of the traits
listed on the chart and below and place your alleles in the chart. Do the
same for your partner.
4. If you know you show the dominant trait and don’t know what your
second allele will be you must flip the penny. Heads is dominant
(upper case) and tails is recessive (lower case).
5. Construct a Punnett square to see all the possible outcomes for your
child! Make sure you label the squares with the trait you are crossing so
you can identify it later as you will need to place it on your butcher
paper.
6. Use the penny and the square chart to find which trait your child will
get!
7. Fill in the alleles and traits for your child!
8. Draw the teenage version of your child by tracing your partner, then
drawing the traits in. All Traits must be easily noticeable on the large
butcher paper.
9. Draw and label all your punnett squares on the paper with your child
and create a chart, like the one below, for all 25 traits that has the
Mom’s Genotype and Phenotype, Dad’s Genotype and Phenotype, and
the Child’s Genotype and Phenotype. The chart is shown on the next
page!
10. You will see a list and description of the traits, including
dominant/recessive on the 3rd page!
List of Dominant/Recessive Traits:
Hairy Fingers, Eyebrow Position, Gender, Face Shape, Chin Shape, Dimple in Chin,
Freckles, Dimples in Cheek, Lip thickness, Eyebrows, Eye shape, Eyelashes, Ear
Shape, Ear lobes, Widow’s Peak
List of Incomplete Dominant Traits:
Skin Color, Hair Shape, Color of eyebrows, eye distance, eye size, mouth size, nose
size, Birth mark(mole)
List of Multiple Allele Traits: (do these last)
Hair color and Eye color
Grading: -2 points for each mistake on the Punnett Squares, Chart, or Child.
-10 if genotypes/phenotypes are not listed on the chart for either parent or child.
Trait
Gender
Shape of
Face
Chin
Shape
Dimple in
Chin
Freckles
Dimples in
cheek
Lip
Thickness
Eye Brows
Eye Shape
Eyelashes
Ear Shape
Ear Lobes
Widow’s
Peak
Hairy
Knuckles
Eyebrow
Position
Hair
Shape
Skin Color
Eyebrow
Color
Eye
distance
Eye size
Mouth
Size
Nose Size
Birth
Mark
Hair Color
Eye Color
Mom’s Mom’s
Geno. Pheno.
XX
RR
female
Round
be consistent with the information provided in
Explanation of Traits
Dad’s
Geno.
Dad’s
Pheno.
XY
rr
male
Square
Child’s
Geno.
?
Rr
Child’s
Pheno.
Girl/Boy
Round
Gender – neither dominant or recessive, the father passes on either an X
chromosome(It’s a girl)or the Y chromosome (It’s a boy)
Dominant/Recessive
Face Shape - Round is dominant, Square is recessive
Chin Shape – Very Noticeable(chin sticks out from face) is dominant, Less
Noticeable(chin does not stick out) is recessive
Dimple in Chin – No dimple is dominant, dimple is recessive
Freckles – Freckles are dominant, No Freckles are recessive
Dimples in cheek – Dimples are dominant, No dimples are recessive
Lip thickness – thick is dominant, thin is recessive
Eyebrows – Bushy is dominant, fine (thin) is recessive
Eye Shape – Wide (almond shape) is dominant, Round is recessive
Eyelashes – Long is dominant, short is recessive
Ear shape – Long ears are dominant, and Round ears are recessive
Ear lobes – Free (dangling lobes) are dominant, attached lobes are recessive
Widow’s Peak – Present is dominant, absent is recessive
Hairy Knuckles – a hairy 2nd knuckle is dominant, and no hair on the 2nd knuckle is
recessive
Eyebrow position (un-ibrow) – connected eyebrows are dominant, and not
connected is recessive
Incomplete Dominance Traits – traits will blend, no dominance or recessive
characteristics
Skin Color (SS, Ss, and ss, base this off of a particular ethnic group) – dark skin is
SS, medium skin is Ss, and light skin is ss
Hair Shape(HH, Hh, and hh) – Curly Hair is HH, Wavy hair is Hh, and Straight Hair
is hh
Eyebrow color (EE. Ee, and ee) – Darker than hair is EE, same as hair is Ee, and
lighter than hair is ee
Eye distance (EE, Ee, and ee) – close together is EE, average distance is Ee, and far
apart is ee
Eye size (EE, Ee, and ee) – Large is EE, medium is Ee, and small is ee
Mouth size (MM, Mm, mm) – Long is MM, medium is Mm, and small is mm
Nose size (NN, Nn, and nn) – Big is NN, medium is Nn, and small is nn
Birth mark (BB, Bb, and bb – this is a mole on the cheek) – mole on left cheek is
BB, mole on right cheek is Bb, and no mole is bb
Multiple Allele Traits – for this lab, we will assume that only 2 gene pairs
control hair and eye color (it is actually more than 2 gene pairs).
Hair color – You will need to analyze what color your hair is naturally and then if
there are 2 options for that hair color below, flip a coin to see which one you will
have
Gene Pair
Hair Color
Gene Pair
Hair Color
AABB
Black
Aabb
Regular blond
AABb
Black
aaBB
Dark Blond
AAbb
Red
aaBb
Regular blond
AaBB
Brown
aabb
Pale blond
AaBb
Brown
Eye Color
Gene Pair
AABB
AABb
AAbb
AaBB
AaBb
Eye Color
Deep Brown
Deep Brown
Brown/Hazel
Greenish brown
Brown/Hazel
Gene Pair
Aabb
aaBB
aaBb
aabb
Eye Color
Grayish blue
Green
Dark blue
Pale blue
Analysis and Conclusions
1. Inferring What are the possible genotypes of the parents of an
offspring who has wavy (Hh) hair?
2. Predicting Would you predict that another pair of students in your
class would have an offspring genetically identical to yours? Support
your answer.nlikely.
3. Drawing Conclusions Do you think anyone in your class has all the
same genetic traits that you have? Explain your answer., do genetic trai
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?
are coded f
or by seve
alnes.
Going Further
Some inherited diseases cause an individual to have mental and physical
impairments or even die before reaching reproductive age. Using library
or Internet resources, read about one of these diseases, Create a
presentation or write a one page double spaced report about what is
understood about its transmission, and in what types of populations it
tends to occur. Some examples of inherited diseases include Cystic
Fibrosis, Duchenne muscular dystrophy, Tay-Sachs disease,
Huntington’s Disease, Otosclerosis, Down Syndrome, Sickle Cell
Disease, Turner Syndrome, Cri-du-Chat Syndrome, and Krabbe’s
disease.
OR
Environmental Factors often play a role in some inherited traits
changing. This is called nature vs. nuture. Some environmental factors
such as exposure to sunlight, diet, and hair treatments are very
common, yet many others are present but harder to acknowledge.
Research environmental effects on genetics and develop a comic strip
illustrating 3 environmental factors and how they may change your
child’s appearance. Include the reaction of others (parents, family, and
friends to the changes your child have made.