Class # ____: Pedigree Problems
Name: __________________________ Core 1 2 3
Activity 1: What is a Genetics Counselor?
Genetic counselors are health professionals with specialized graduate degrees and experience in the areas of medical
genetics and counseling. Most enter the field from a variety of disciplines, including biology, genetics, nursing,
psychology, public health and social work. According the Bureau of Labor Statistics, Genetics Counselors earn an
average annual salary of $67,800.
Go to this link to learn more about Genetics Counseling:
http://video.about.com/psychology/What-Is-a-Genetics-Counselor-.htm
1. Genetics Counselors are part of a m___________________ team.
2. What kinds of things do Genetics Counselors to help individuals and families? _______________________
_________________________________________________________________________________________
3. You Choose! Circle one choice and explain your reasons. I might like OR I would definitely not like
to be a Genetic Counselor, because _____________________________________________________________
_________________________________________________________________________________________.
4. What is a genogram? _____________________________________________________________________
5. What is the synonym on your vocabulary list that means the same thing as a genogram? ________________
Activity 2: How do Genetics Counselors make and read pedigrees?
Go to this link to learn what the symbols in a genogram/ pedigree mean. (4:23)
http://www.youtube.com/watch?v=Wuk0W10EveU
5. Create a legend for the symbols in a pedigree diagram.
Characteristic
Boy = square
Girl = circle
Carrier = Half-shaded in shape
Genotype
X Y
Symbol
Boy Carrier
Girl Carrier
Recessive Affected = Completely shaded
Boy Affected
Girl Affected
Homozygous Unaffected = Unshaded shape
Boy Unaffected
Girl Unaffected
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Activity 3: What would your family pedigree look like? Here are a few more symbols to show relationships
between individuals on a pedigree chart.
6. In the space below, create a pedigree for your family including your
parents and siblings.
 Your parents would be the I Generation
 You and your siblings are the II Generation.
 You should show your brothers and sisters in the order they were
born with the oldest shown the further to the left.
The _________________ Family
7. Add everyone’s first name.
8. Add the Generation Number I and II in the margin. Add individual numbers (Generation II – birth order
number) to all siblings.
Activity 4: Help! I need a Pet Genetic Counselor. Can you help me with my bunnies?
Consider the following pedigree for a poor family of bunny rabbits with a
terrible recessive trait for being allergic to carrots.
 C = no carrot allergy
 c = carrot allergy
9. Which numbered bunnies have the allergy? ______, ______, ______
10. For bunny II-2 to have the allergy, the parents must be what?
a) heterozygous b) homozygous recessive c) homozygous dominant
11. How should Generation I be shaded? __________ Do it.
11. If I wanted to breed bunny number III – 3 with a rabbit who had
the allergy, what would the chances be of any of the off-spring having the allergy? _________________
12. Prove it! (Hint: You may want to use a Punnett Square.)
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Activity 5: How can you tell if a trait is a sex-linked trait or an autosomal trait by looking at a pedigree?
IF  Then Tables can be a powerful tool for helping to make decisions. Consider the following 3 types of
inheritance systems:
A) Autosomal traits
B) X-linked Sex-linked Traits
C) Y-linked Sex-linked Traits
Read each IF  Then scenario in the table below.
IF it is an autosomal trait:
Then:
IF X-linked, Sex-linked Traits
Then:
there will be approximately equal
a far greater number of males will
numbers of males and females with have the trait or condition than
the trait or condition.
females since most are X-linked
recessive.
IF Y-linked, Sex-linked Traits
Then:
only males will have the trait or
condition.
Imagine you are helping with a research project for a medical team at Children’s Hospital. Below there are 3
family trees. Use the following If/ Then Table above to analyze each of the pedigrees.
Determine if it is a(n):
A) Autosomal trait
B) X-linked Sex-linked Traits
C) Y-linked Sex-linked Traits
13. Type of Trait/ Condition
15. Type or Trait/ Condition
17. Type or Trait/ Condition
__________________________
__________________________
________________________
14. Why is it this type?
16. Why is it this type?
18. Why is it this type?
___________________________
__________________________
________________________
___________________________
__________________________
________________________
___________________________
__________________________
________________________
___________________________
__________________________
________________________
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Activity 6: The Nelson Family needs a Genetic Counselor. They are counting you.
Use the information in the story below to draw your own pedigree and help this family learn why their
child has albinism.
John and Mary have just had their second baby, a boy, born with the recessive trait of albinism. Their first baby, also a
boy was normal. Genetic testing showed no trace of the disorder in the first baby.
Mary knew of a distant uncle that had albinism but there is no other history of the disorder in her family.
John had three sisters, none of which were albino. Further genetic testing confirmed that two of the sisters had no marker
for albinism, but the third sister, Greta, was a carrier. Greta and her husband had two girls with no trace of the disorder.
John’s parents decided it was time to tell John something he didn’t know. John had a baby brother that was born albino,
but died young, long before John was born.
John’s father, Fred, had a brother that was tested and showed no trace for albinism. Fred’s two sisters tested as carriers
of the trait.
Fred’s father, Barney, was dead, so he couldn’t be tested, but his wife Melba, knew he wasn’t albino. Melba also wasn’t
albino, but she had a brother that was albino. She remembers that Barney’s father was also albino.
19. Use this information to draw a pedigree below beginning with Barney’s mother and father, and
ending with John and Mary’s two children. (Hint: Work backwards from the bottom to the top of the
diagram.)
20. John and Mary Nelson had an albino son, because _____________________________________________
_________________________________________________________________________________________
_________________________________________________________________________________________
_________________________________________________________________________________________
_________________________________________________________________________________________
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