WGU D115 OBJECTIVE ASSESSMENT
(OA) EXAM 2024-2025 COMPLETE UNIT
1-UNIT 7 QUESTIONS AND CORRECT
DETAILED ANSWERS WITH
RATIONALES
Which type of genetic disease affects males more frequently than females?
Sex-linked recessive
Autosomal recessive
Autosomal dominant
Sex-linked dominant – answer Sex-Linked recessive. Since males only have one X and
one Y, if the affected chromosome has the illness, it will be expressed.
In which two conditions are chromosomal abnormalities the leading known cause?
Intellectual disability
Respiratory disorders
Fetal miscarriage
Cardiovascular disease
Mental illness
Check My Answer – answer Intellectual disability and fetal miscarriage. Chromosome
abnormalities are the leading known cause of intellectual disability and fetal
miscarriage.
What are three examples of prenatal diagnostic studies?
Drug-sensitivity testing
Chorionic villus sampling (CVS)
Microscopy of cervical mucosa
Preimplantation genetic testing (PGT)
Amniocentesis – answer Chorionic villus sampling (CVS), amniocentesis, and
preimplantation genetic testing (PGT) are examples of prenatal diagnostic studies and
are performed in vitro. CVS is a form of genetic testing that provides genetic information
found in utero and is usually performed between weeks 11 and 14 of pregnancy. An
amniocentesis is a form of genetic testing that evaluates amniotic fluid and is usually
performed during the second trimester, between weeks 15 and 20 of pregnancy. PGT is
performed on the embryo prior to implantation.
, Which genetic disorder is characterized by the presence of a zygote having one
chromosome with a normal complement of genes and one chromosome with a missing
gene?
Klinefelter syndrome
Down syndrome
Cri du chat syndrome
Turner syndrome – answer Cri du chat syndrome (translated as "cry of the cat") is
caused by a DNA deletion. This term describes the cry often heard from a baby affected
by the syndrome. Cri du chat syndrome can present as a microcephalic, low birth-
weight baby with a piercing cry.
How can an X-linked recessive disease skip generations?
Mothers cannot pass X-linked genes to their sons.
Females are hemizygous for the X chromosome.
The disease can be transmitted through female carriers.
These diseases need only one copy of the gene in females. – answer The disease can
be transmitted through female carriers.
Since females have two copies of the X chromosome, the mother may provide an
unaffected X to a daughter or son. Furthermore, a daughter may not show signs of the
disease because she has the other X (the only X the father can give to a female) to
cancel it out.
Which type of risk is referred to as the ratio of the disease rate among the entire
population to the disease rate in an unexposed population?
Relative
Attributable
Contingency
Causal – answer Relative risk is a ratio of probability, not an actual occurrence of
disease.
What are the empirical risks for most multifactorial diseases based on?
Direct observation
Chromosomal testing
Relative risks
Liability thresholds – answer Many factors from lifestyle to genetics affect multifactorial
diseases. Observation and evaluation of each case individually provides the most
thorough and accurate assessment.
What refers to the silenced gene of a gene pair.
Imprinted, activated, mutated, altered – answer The imprinted gene is the silent gene of
a gene pair.
(OA) EXAM 2024-2025 COMPLETE UNIT
1-UNIT 7 QUESTIONS AND CORRECT
DETAILED ANSWERS WITH
RATIONALES
Which type of genetic disease affects males more frequently than females?
Sex-linked recessive
Autosomal recessive
Autosomal dominant
Sex-linked dominant – answer Sex-Linked recessive. Since males only have one X and
one Y, if the affected chromosome has the illness, it will be expressed.
In which two conditions are chromosomal abnormalities the leading known cause?
Intellectual disability
Respiratory disorders
Fetal miscarriage
Cardiovascular disease
Mental illness
Check My Answer – answer Intellectual disability and fetal miscarriage. Chromosome
abnormalities are the leading known cause of intellectual disability and fetal
miscarriage.
What are three examples of prenatal diagnostic studies?
Drug-sensitivity testing
Chorionic villus sampling (CVS)
Microscopy of cervical mucosa
Preimplantation genetic testing (PGT)
Amniocentesis – answer Chorionic villus sampling (CVS), amniocentesis, and
preimplantation genetic testing (PGT) are examples of prenatal diagnostic studies and
are performed in vitro. CVS is a form of genetic testing that provides genetic information
found in utero and is usually performed between weeks 11 and 14 of pregnancy. An
amniocentesis is a form of genetic testing that evaluates amniotic fluid and is usually
performed during the second trimester, between weeks 15 and 20 of pregnancy. PGT is
performed on the embryo prior to implantation.
, Which genetic disorder is characterized by the presence of a zygote having one
chromosome with a normal complement of genes and one chromosome with a missing
gene?
Klinefelter syndrome
Down syndrome
Cri du chat syndrome
Turner syndrome – answer Cri du chat syndrome (translated as "cry of the cat") is
caused by a DNA deletion. This term describes the cry often heard from a baby affected
by the syndrome. Cri du chat syndrome can present as a microcephalic, low birth-
weight baby with a piercing cry.
How can an X-linked recessive disease skip generations?
Mothers cannot pass X-linked genes to their sons.
Females are hemizygous for the X chromosome.
The disease can be transmitted through female carriers.
These diseases need only one copy of the gene in females. – answer The disease can
be transmitted through female carriers.
Since females have two copies of the X chromosome, the mother may provide an
unaffected X to a daughter or son. Furthermore, a daughter may not show signs of the
disease because she has the other X (the only X the father can give to a female) to
cancel it out.
Which type of risk is referred to as the ratio of the disease rate among the entire
population to the disease rate in an unexposed population?
Relative
Attributable
Contingency
Causal – answer Relative risk is a ratio of probability, not an actual occurrence of
disease.
What are the empirical risks for most multifactorial diseases based on?
Direct observation
Chromosomal testing
Relative risks
Liability thresholds – answer Many factors from lifestyle to genetics affect multifactorial
diseases. Observation and evaluation of each case individually provides the most
thorough and accurate assessment.
What refers to the silenced gene of a gene pair.
Imprinted, activated, mutated, altered – answer The imprinted gene is the silent gene of
a gene pair.
