Pedigree Practice Problems

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Pedigree Practice
What is the pattern of inheritance depicted? AUTOSOMAL DOMINANT
Write the genotypes for all individuals --use "A" to represent a dominant
allele & "a" to represent a recessive allele, if one allele is unknown, use a "?"
to represent that allele.
Generation #1 - Aa, aa
Generation #2 - Aa, Aa, aa, A?, aa, Aa, aa, Aa
Generation #3 - aa, Aa, aa, aa, aa, Aa
NOT X-linked because a female who has the trait has a son who does
not (not possible with x-linked).
Not Autosomal recessive - two parents who express the trait have a
child who does not express it. (Not possible with autosomal recessive,
since parents would only have recessive alleles to pass on).
Pedigree Practice
Answer the questions about the pedigree chart below.
What is the pattern of inheritance depicted?
__________________________
WHY are the other patterns ruled out?
Write the genotypes for all individuals --use "A" to represent a dominant
allele & "a" to represent a recessive allele, if one allele is unknown, use a "?"
to represent that allele.
Generation #1 Generation #2 Generation #3 -
Pedigree Practice #1
In the pedigree chart below, the filled symbols represent individuals who
express a given trait - circles are females, squares are males. If each line
represents one generation What is the pattern of inheritance depicted? ________________
Why isn't it the other two patterns of inheritance?
Write the genotypes for all individuals --use "A" to represent a dominant
allele & "a" to represent a recessive allele, if one allele is unknown, use a "?"
to represent that allele.
Generation #1 –
Generation #2 –
Generation #3 -
Pedigree Practice #1 - ANSWERS
In the pedigree chart below, the filled symbols represent individuals who
express a given trait - circles are females, squares are males. If each line
represents one generation What is the pattern of inheritance depicted? AUTOSOMAL RECESSIVE
Write the genotypes for all individuals --use "A" to represent a dominant
allele & "a" to represent a recessive allele, if one allele is unknown, use a "?"
to represent that allele.
Generation #1 --aa, Aa
Generation #2 -- aa, Aa, Aa, aa, Aa, Aa, Aa, aa
Generation #3 --Aa, aa, aa, Aa, Aa, aa
NOT X-linked because a female who has the trait has a son who does
not (not possible with x-linked).
Not Autosomal dominant - two parents who do not express the trait
have a child who does (not possible with autosomal dominant, since
parents would only have recessive allele).
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