WGU BIOCHEMISTRY FINAL EXAM SCRIPT
2026 QUESTIONS WITH FULL SOLUTIONS
◉ A black female mouse mates with a white male mouse and
produces a litter of all gray mice. Which inheritance pattern can be
used to describe this situation?
Complete Dominance
Recessive
Incomplete Dominance
Codominance. Answer: Incomplete Dominance
Feedback
Incomplete dominance produces a blended phenotype.
◉ Both pedigrees show the inheritance of von Willebrand disease, a
bleeding disorder in which platelets fail to clot properly. There are
different types of von Willebrand disease that exhibit different
inheritance patterns. Type I is inherited in an autosomal dominant
fashion, while type III is autosomal recessive. Which of the following
statements best describes the families depicted in the pedigrees
below?
,Family 1 has type III and Family 2 is unlikely to have either of these
two types.
Family 1 has type I and Family 2 has type III
Both families have type I.
Family 1 has type III and Family 2 has type I. Answer: Family 1 has
type III and Family 2 has type I
Feedback
Family 1 has carrier parents present and both males and females are
affected, so it is type III, autosomal recessive. Family 2 does not have
carrier parents and affected males do have unaffected daughters, so
it is type I, autosomal dominant.
◉ What is the expected probability that a child will have an
autosomal dominant disease if their father is heterozygous for the
allele and their mother is homozygous for the normal allele?
0%
25%
50%
100%. Answer: 50%
Feedback
Aa X aa => 50% Aa diseased, 50% aa normal
,◉ Craniofrontonasal Dysplasia is an X-linked Dominant disorder.
This condition is very rare and is caused by mutations in the Ephrin
B-1 gene. Which one of the following pedigrees portrays the familial
inheritance pattern of this X-linked Dominant disorder?
Option 1
Option 2
Option 3
Option 4. Answer: Option 4
Feedback
To first differentiate between dominant and recessive, check to see if
any carriers are present in any generation. Options 1 and 3 are
Recessive inheritance patterns because they both contain the
pattern where two parents are unaffected and have a child that is
affected. Option 1 is X-linked Recessive because only males are
affected in the entire pedigree. Option 3 is Autosomal Recessive
because there is an affected female. Since Options 2 and 4 are both
Dominant, we look to see which one has a pattern where an affected
father has daughters that are all affected. Option 2 has an affected
father with an affected son, so this must be Autosomal Dominant.
Option 4 demonstrates an affected father passing the disease down
to all of his daughters, so the answer is Option 4.
, ◉ Two healthy individuals give birth to a child that has Bloom
Syndrome. From this information, it can be concluded that Bloom
syndrome is inherited in a ________ manner.
recessive
dominant
sex-linked. Answer: recessive
Feedback
Carrier parents are parents who do not have a particular trait, such
as a disease, but that trait shows up in their offspring. The presence
of carrier parents signifies that the trait is recessive.
◉ The Punnett Squares below represent three different types of
dominance. Which answer choice correctly identifies the different
types of Dominance?
1. A. Complete Dominance; B. Incomplete Dominance; C.
Codominance
2. A. Codominance; B. Complete Dominance; C. Incomplete
Dominance
3. A. Incomplete Dominance; B. Complete Dominance; C.
Codominance
2026 QUESTIONS WITH FULL SOLUTIONS
◉ A black female mouse mates with a white male mouse and
produces a litter of all gray mice. Which inheritance pattern can be
used to describe this situation?
Complete Dominance
Recessive
Incomplete Dominance
Codominance. Answer: Incomplete Dominance
Feedback
Incomplete dominance produces a blended phenotype.
◉ Both pedigrees show the inheritance of von Willebrand disease, a
bleeding disorder in which platelets fail to clot properly. There are
different types of von Willebrand disease that exhibit different
inheritance patterns. Type I is inherited in an autosomal dominant
fashion, while type III is autosomal recessive. Which of the following
statements best describes the families depicted in the pedigrees
below?
,Family 1 has type III and Family 2 is unlikely to have either of these
two types.
Family 1 has type I and Family 2 has type III
Both families have type I.
Family 1 has type III and Family 2 has type I. Answer: Family 1 has
type III and Family 2 has type I
Feedback
Family 1 has carrier parents present and both males and females are
affected, so it is type III, autosomal recessive. Family 2 does not have
carrier parents and affected males do have unaffected daughters, so
it is type I, autosomal dominant.
◉ What is the expected probability that a child will have an
autosomal dominant disease if their father is heterozygous for the
allele and their mother is homozygous for the normal allele?
0%
25%
50%
100%. Answer: 50%
Feedback
Aa X aa => 50% Aa diseased, 50% aa normal
,◉ Craniofrontonasal Dysplasia is an X-linked Dominant disorder.
This condition is very rare and is caused by mutations in the Ephrin
B-1 gene. Which one of the following pedigrees portrays the familial
inheritance pattern of this X-linked Dominant disorder?
Option 1
Option 2
Option 3
Option 4. Answer: Option 4
Feedback
To first differentiate between dominant and recessive, check to see if
any carriers are present in any generation. Options 1 and 3 are
Recessive inheritance patterns because they both contain the
pattern where two parents are unaffected and have a child that is
affected. Option 1 is X-linked Recessive because only males are
affected in the entire pedigree. Option 3 is Autosomal Recessive
because there is an affected female. Since Options 2 and 4 are both
Dominant, we look to see which one has a pattern where an affected
father has daughters that are all affected. Option 2 has an affected
father with an affected son, so this must be Autosomal Dominant.
Option 4 demonstrates an affected father passing the disease down
to all of his daughters, so the answer is Option 4.
, ◉ Two healthy individuals give birth to a child that has Bloom
Syndrome. From this information, it can be concluded that Bloom
syndrome is inherited in a ________ manner.
recessive
dominant
sex-linked. Answer: recessive
Feedback
Carrier parents are parents who do not have a particular trait, such
as a disease, but that trait shows up in their offspring. The presence
of carrier parents signifies that the trait is recessive.
◉ The Punnett Squares below represent three different types of
dominance. Which answer choice correctly identifies the different
types of Dominance?
1. A. Complete Dominance; B. Incomplete Dominance; C.
Codominance
2. A. Codominance; B. Complete Dominance; C. Incomplete
Dominance
3. A. Incomplete Dominance; B. Complete Dominance; C.
Codominance
