AP Biology Pedigree Problem Set

AP Biology Pedigree Problem Set

AP Biology Pedigree Problem Set provides essential exercises for understanding genetic inheritance patterns through pedigrees. It includes various scenarios involving traits such as tongue-rolling, blood types, and earlobe attachment, allowing students to practice determining genotypes and constructing pedigrees. Designed for AP Biology students preparing for exams, this resource emphasizes the application of Mendelian genetics principles. The problem set features multiple family scenarios, encouraging critical thinking and problem-solving skills in genetics.

Key Points

  • Includes exercises on tongue-rolling inheritance patterns and genotypes.
  • Covers blood type inheritance with scenarios involving AB and B blood types.
  • Features earlobe attachment genetics with dominant and recessive traits.
  • Provides practice in constructing pedigrees for various genetic traits.
  • Aliusa
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AP Biology Pedigree Problem Set
NOTE: Some genotypes cannot be determined in these problems- write ALL possible for those.
1. Jim and Jill are both tongue-rollers (TT or Tt – you determine which). They have 4
children. The children are shown in the pedigree below. Write in the genotype for all
individuals on the pedigree. NOTE: In this pedigree, the individuals are only shown as
having the trait- it is up to you to determine if they are homozygous or heterozygous-
half-shaded boxes are NOT being used for this example.
2. Adriana and Javier have 3 children. Adriana has type AB blood and Javier has type B
blood. List the missing genotypes for the pedigree shown below. HINT: Work from
bottom to top.
I
A
I
B
I
B
I
B
I
B
i
Blood Genotypes
A = I
A
I
A
, I
A
i
B = I
B
I
B
, I
B
i
AB = I
A
I
B
0 = ii
3. Use the information you have learned about pedigrees to construct a pedigree for the
following family. Use E for earlobe attachment. Shade the whole symbol for dominant
traits and half of the symbol for heterozygous traits. Unattached earlobes are
dominant to attached.
a. Father = heterozygous for unattached earlobes.
b. Mother = homozygous recessive for attached earlobes.
c. Male Child 1 = heterozygous
d. Male Child 2 = homozygous recessive
e. Female Child = heterozygous
4. Construct a pedigree for the following family. You may have to work backwards on some
of the individuals. Fill in the missing phenotypes for individuals in the list below. You
have been given enough clues to fill the genotypes (remember- if you cannot determine
if they are homozygous dominant or heterozygous, then write both).
a. Use a ruler to make the diagram neat. Shade the whole symbol for dominant
individuals and shade half of the symbol for heterozygous individuals and there is
no shading for recessive. Use the back or another sheet of paper if you need more
room.
b. Dimples (D) are dominant over no dimples.
c. John = Dimples
d. Mary = Dimples
e. Luke (child of John and Mary) = Dimples (homozygous)
f. Sarah (child of John and Mary) = No Dimples
g. Mark (child of John and Mary) = Dimples
h. Elizabeth (wife of Luke) = No Dimples
i. Johnny (child of Luke and Elizabeth) = ? _____________________
j. Matthew (child of Luke and Elizabeth) = ? ____________________
k. Ann (child of Luke and Elizabeth) = ? ________________________
l. Margaret (wife of Mark) = Dimples
m. Katherine (child of Margaret and Mark) = heterozygous dimples
n. Grace (child of Margaret and Mark) = homozygous dimples
o. Claire (child of Margaret and Mark) = Dimples
p. Michael (husband of Claire) = No Dimples
q. Caroline (child of Claire and Michael) = Heterozygous Dimples
5. A man and woman marry. They have five children, 2 girls and 3 boys. The mother is a
carrier of hemophilia, an X-linked disorder. She passes the gene on to two of the boys
who died in childhood and one of the daughters is also a carrier. Both daughters marry
men without hemophilia and have 3 children (2 boys and a girl). The carrier daughter
has one son with hemophilia. One of the non-carrier daughter’s sons marries a woman
who is a carrier and they have twin daughters. Construct a pedigree to show the
inheritance pattern of this family. What is the percent chance that each
daughter will also be a carrier?
Type
A
6. The great-great maternal grandmother of a boy was a carrier for color-blindness, an X-
linked disorder. His great uncle on his mother’s side was colorblind but this great
uncle’s father was unaffected. The boy’s mother has 2 brothers (1 colorblind, 1
unaffected) and 1 sister (unaffected). The boy’s grandmother on his mother’s side had 1
brother who was colorblind and 3 sisters. Two of these sisters were unaffected and one
was a carrier. The boy’s great grandmother on his mother’s side had 4 sisters. The boy
has one unaffected sister and he is colorblind. Construct a pedigree to show the
inheritance pattern of this family. What is the probability of the boy’s sons being
colorblind if he marries a non-carrier?
7. An unaffected man marries a woman who is a carrier for Duchenne Muscular
Dystrophy, which is attributed to an X-linked gene. They have four children, one with
Duchenne, one carrier daughter and a daughter and son who are unaffected. The child
with Duchenne Muscular Dystrophy dies in childhood. The carrier daughter marries
and has three children of her own, two of which are carriers and one of which is
unaffected. Construct a pedigree to show the inheritance pattern of this family. What
is the most likely sex of these two carrier children given the fact that they
are unaffected by the X-linked gene?
X
H
= normal
X
h
= hemophilia (a genetic disease or abnormality)
Y = Y chromosome (males only)
X
C
= normal
X
c
= Colorblind (a genetic disease or abnormality)
Y = Y chromosome (males only)
X
D
= normal
X
d
= Duchenne MD (a genetic disease or abnormality)
Y = Y chromosome (males only)
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Faqs of AP Biology Pedigree Problem Set
How do you determine the genotypes in a pedigree?
Determining genotypes in a pedigree involves analyzing the inheritance patterns of traits across generations. By observing the phenotypes of parents and their offspring, one can infer whether individuals are homozygous or heterozygous for a trait. For example, if both parents exhibit a dominant trait, their genotypes could be either homozygous dominant or heterozygous. The presence of recessive traits in offspring can help clarify the parents' genotypes.
What is the significance of using pedigrees in genetics?
Pedigrees are crucial in genetics as they visually represent the inheritance of traits within a family over generations. They help identify carriers of genetic conditions, understand the likelihood of traits being passed on, and track the occurrence of genetic disorders. By analyzing pedigrees, geneticists can predict the probability of offspring inheriting specific traits, making them an essential tool in genetic counseling and research.
What traits are explored in the AP Biology Pedigree Problem Set?
The AP Biology Pedigree Problem Set explores various traits including tongue-rolling, blood types, earlobe attachment, and dimples. Each trait is analyzed through different family scenarios, allowing students to practice identifying genotypes and constructing pedigrees. This diversity of traits helps students understand the principles of Mendelian genetics and the complexities of inheritance patterns.
How does blood type inheritance work in pedigrees?
Blood type inheritance is determined by multiple alleles, including A, B, and O. In a pedigree, individuals can have genotypes such as IAIA, IAi, IBIB, IBi, or ii, which correspond to blood types A, B, AB, and O, respectively. By analyzing the blood types of parents and their children, one can infer possible genotypes and predict the likelihood of certain blood types appearing in future generations.