Pedigree

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Name ______________________________ Class ___________________ Date __________________
Quick Lab
Pedigree Analysis
You will practice interpreting a pedigree. The pedigree to the right shows the
presence or absence of the albinism trait in several generations of a family.
K
L
M
N
Analysis
1. Determine whether the albinism trait is dominant or recessive. Explain your
reasoning.
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2. Determine the genotypes for females A & B.
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3. Based upon your conclusion to Question 1 & 2, determine what the genotype
is for the parents of Female A and Female B.
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Name ______________________________ Class ___________________ Date __________________
4. Determine the genotypes as many of the family members of this pedigree as
possible and label each genotype in the pedigree above. Use the following
designations in and place the numbers of each on the lines below:
AA = Homozygous dominant. _________________________________________
Aa = Heterozygous: _________________________________________________
aa = Homozygous recessive: __________________________________________
?? = Not enough information to conclude: ________________________________
5. Critical Thinking. Applying Information. Suppose that Female C is
homozygous dominant and produces children with hypothetical Male D. If
Male D is heterozygous, what is the % chance that the children will have the
albinism trait? What is the % chance that a child will be a carrier? Complete
the Punnet square to show your work.
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6. Analysis. How does the Punnet square apply to the offspring? For example,
if one child matches the genotype of the upper left quadrant of the Punnet
square, can the child’s sibling (brother or sister) be the same genotype for the
trait or does the Punnet square imply that once the genotype is taken, no other
siblings can have that genotype. (See siblings K, L, M, & N). Explain.
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7. Summarize. Name 2 things that a Pedigree can show you.
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