BIO 117 FINAL EXAM- UPDATED
WITH QUESTIONS AND VERIFIED CORRECT
ANSWERS
What is a pedigree? - CORRECT ANSWERA pedigree is a chart of family connections
that shows the appearance of a trait through generations
Pedigrees show the ______________ of family members. - CORRECT ANSWER
Phenotypes
What is the difference between a genetic abnormality and a genetic disorder? -
CORRECT ANSWER A genetic abnormality is a rare or uncommon version of a trait,
such as having six fingers on a hand or having a web between toes. Genetic
abnormalities are not inherently life threatening, and how you view them is a matter of
opinion. By contrast, a genetic disorder sooner or later causes medical problems that
may be severe. A genetic disorder is often characterized by a specific set of symptoms
(a syndrome)
Know the difference between autosomal dominant, autosomal recessive, X-linked
dominant, and X-linked recessive. - CORRECT ANSWER
What is the autosomal dominant pattern? - CORRECT ANSWER A trait associated with
a dominant allele on an autosome appears in people who are heterozygous for it as well
as those who are homozygous. Such traits appear in every generation of a family, and
they occur with frequency in both sexes. When one parent is heterozygous and the
other is homozygous for the recessive allele, each child has a 50% chance of inheriting
the dominant allele and having the associated trait
What are examples of autosomal dominant disorders? - CORRECT ANSWER
Achondroplasia (a form of hereditary dwarfism). Huntington's disease (an inherited
condition in which nerve cells in the brain break down over time)
What is the autosomal recessive pattern? - CORRECT ANSWER A recessive allele on
an autosome is expressed only in homozygous individuals, so traits associated with the
allele tend to skip generations. Both sexes are equally affected. Heterozygous
individuals are called carriers because they have the allele but not the trait. Any child of
two carriers has a 25% chance of inheriting the allele from both parents and developing
the trait
What is an example of an autosomal recessive disorder? - CORRECT ANSWER Tay-
Sachs disease. Typically newborns homozygous for a Tay-Sachs allele seem normal,
but within three to six months they become irritable, listless, and may have seizures as
, the lipid accumulates in their nerve cells. Blindness, deafness, and paralysis follow.
Affected children usually die by age five. Albinism is also inherited in an autosomal
recessive pattern
What is the X-Linked recessive pattern? - CORRECT ANSWER A recessive allele on
an X chromosome leaves two clues when it causes a genetic disorder. First, an affected
father never passes the disorder to a son, because all children who inherit their father's
X chromosome are female. Thus, a heterozygous female is always the bridge between
an affected male and his affected grandson. Second, the disorder appears in males
more often than in females. This is because the males who carry the allele have the
disorder, but not all heterozygous females do. Only about half of a heterozygous
female's fell express the recessive allele (Barr bodies)
An affected father never passes the x-linked recessive disorder to a ________. -
CORRECT ANSWER Son (All the children who inherit the father's X chromosome are
female)
Why does X-linked recessive disorders appear more in males? - CORRECT ANSWER
The X-linked recessive disorders appear more in males. This is because it males need
only one recessive allele to have the disorder. Females need both recessive alleles
What is an example of an X-linked recessive disorder? - CORRECT ANSWER Color
blindness
What is color blindness? - CORRECT ANSWER Color blindness refers to a range of
conditions in which an individual cannot distinguish among colors in the spectrum of
visible light. These conditions are typically inherited in an X-linked recessive pattern,
because most of the genes involved in color vision are on the X-chromosome
Know the difference between duplication, deletion, inversion, and translocation when it
comes to chromosome changes. - CORRECT ANSWER
What is duplication? - CORRECT ANSWER Repeated section of a chromosome
Why does duplication cause issues? - CORRECT ANSWER Duplications alter gene
dosage. Extra genes lead to extra proteins that are not needed
Some newly occurring duplications, such as the expansion mutation, that cause
Huntington's disease, cause genetic abnormalities or _______. - CORRECT ANSWER
Disorders
What is inversion? - CORRECT ANSWER Structural rearrangement of a chromosome
in which part of the DNA becomes oriented in the reverse direction
What is the issue with inversion? - CORRECT ANSWER Changes the location of a
gene on a chromosome. Changes gene expression
WITH QUESTIONS AND VERIFIED CORRECT
ANSWERS
What is a pedigree? - CORRECT ANSWERA pedigree is a chart of family connections
that shows the appearance of a trait through generations
Pedigrees show the ______________ of family members. - CORRECT ANSWER
Phenotypes
What is the difference between a genetic abnormality and a genetic disorder? -
CORRECT ANSWER A genetic abnormality is a rare or uncommon version of a trait,
such as having six fingers on a hand or having a web between toes. Genetic
abnormalities are not inherently life threatening, and how you view them is a matter of
opinion. By contrast, a genetic disorder sooner or later causes medical problems that
may be severe. A genetic disorder is often characterized by a specific set of symptoms
(a syndrome)
Know the difference between autosomal dominant, autosomal recessive, X-linked
dominant, and X-linked recessive. - CORRECT ANSWER
What is the autosomal dominant pattern? - CORRECT ANSWER A trait associated with
a dominant allele on an autosome appears in people who are heterozygous for it as well
as those who are homozygous. Such traits appear in every generation of a family, and
they occur with frequency in both sexes. When one parent is heterozygous and the
other is homozygous for the recessive allele, each child has a 50% chance of inheriting
the dominant allele and having the associated trait
What are examples of autosomal dominant disorders? - CORRECT ANSWER
Achondroplasia (a form of hereditary dwarfism). Huntington's disease (an inherited
condition in which nerve cells in the brain break down over time)
What is the autosomal recessive pattern? - CORRECT ANSWER A recessive allele on
an autosome is expressed only in homozygous individuals, so traits associated with the
allele tend to skip generations. Both sexes are equally affected. Heterozygous
individuals are called carriers because they have the allele but not the trait. Any child of
two carriers has a 25% chance of inheriting the allele from both parents and developing
the trait
What is an example of an autosomal recessive disorder? - CORRECT ANSWER Tay-
Sachs disease. Typically newborns homozygous for a Tay-Sachs allele seem normal,
but within three to six months they become irritable, listless, and may have seizures as
, the lipid accumulates in their nerve cells. Blindness, deafness, and paralysis follow.
Affected children usually die by age five. Albinism is also inherited in an autosomal
recessive pattern
What is the X-Linked recessive pattern? - CORRECT ANSWER A recessive allele on
an X chromosome leaves two clues when it causes a genetic disorder. First, an affected
father never passes the disorder to a son, because all children who inherit their father's
X chromosome are female. Thus, a heterozygous female is always the bridge between
an affected male and his affected grandson. Second, the disorder appears in males
more often than in females. This is because the males who carry the allele have the
disorder, but not all heterozygous females do. Only about half of a heterozygous
female's fell express the recessive allele (Barr bodies)
An affected father never passes the x-linked recessive disorder to a ________. -
CORRECT ANSWER Son (All the children who inherit the father's X chromosome are
female)
Why does X-linked recessive disorders appear more in males? - CORRECT ANSWER
The X-linked recessive disorders appear more in males. This is because it males need
only one recessive allele to have the disorder. Females need both recessive alleles
What is an example of an X-linked recessive disorder? - CORRECT ANSWER Color
blindness
What is color blindness? - CORRECT ANSWER Color blindness refers to a range of
conditions in which an individual cannot distinguish among colors in the spectrum of
visible light. These conditions are typically inherited in an X-linked recessive pattern,
because most of the genes involved in color vision are on the X-chromosome
Know the difference between duplication, deletion, inversion, and translocation when it
comes to chromosome changes. - CORRECT ANSWER
What is duplication? - CORRECT ANSWER Repeated section of a chromosome
Why does duplication cause issues? - CORRECT ANSWER Duplications alter gene
dosage. Extra genes lead to extra proteins that are not needed
Some newly occurring duplications, such as the expansion mutation, that cause
Huntington's disease, cause genetic abnormalities or _______. - CORRECT ANSWER
Disorders
What is inversion? - CORRECT ANSWER Structural rearrangement of a chromosome
in which part of the DNA becomes oriented in the reverse direction
What is the issue with inversion? - CORRECT ANSWER Changes the location of a
gene on a chromosome. Changes gene expression
