WGU D115 OBJECTIVE ASSESSMENT (OA)
EXAM 2025-2026 COMPLETE UNIT 1-UNIT 7 550
QUESTIONS AND CORRECT DETAILED
ANSWERS WITH RATIONALES ALL THAT YOU
NEED COMPILED TOGETHER
WGU D115 UNIT 1
Which type of genetic disease affects males more frequently than females?
Sex-linked recessive
Autosomal recessive
Autosomal dominant
Sex-linked dominant - CORRECT 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 - CORRECT 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 - CORRECT 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 - CORRECT 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. - CORRECT 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 - CORRECT 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 - CORRECT 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 - CORRECT ANSWER: The imprinted gene is the
silent gene of a gene pair.
What is the primary reason that some older adults have impaired inflammation and
wound healing?
The circulatory system cannot adequately perfuse tissues.
, The underlying chronic illness exists.
The complement is deficient.
The number of mast cells is insufficient. - CORRECT ANSWER: The underlying chronic
illness exists.
A generalized inflammatory response seen in chronic illness depletes the body's
reserves to fight against illness.
Which cells are the body's primary defense against parasite invasion?
B lymphocytes
Eosinophils
Neutrophils
T lymphocytes - CORRECT ANSWER: Eosinophils are the body's primary defense
against parasites.
What Phagocytes bacteria?
eosinophils
macrophages
perforin - CORRECT ANSWER: Macrophages work by eating or phagocytosing
bacteria.
What is the first response to a foreign pathogen?
cytotoxic T
helper T cells
phagocytic - CORRECT ANSWER: Helper T cells
Which characteristic is the most important determinant of immunogenicity when
considering the antigen?
Foreignness
Quantity
EXAM 2025-2026 COMPLETE UNIT 1-UNIT 7 550
QUESTIONS AND CORRECT DETAILED
ANSWERS WITH RATIONALES ALL THAT YOU
NEED COMPILED TOGETHER
WGU D115 UNIT 1
Which type of genetic disease affects males more frequently than females?
Sex-linked recessive
Autosomal recessive
Autosomal dominant
Sex-linked dominant - CORRECT 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 - CORRECT 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 - CORRECT 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 - CORRECT 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. - CORRECT 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 - CORRECT 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 - CORRECT 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 - CORRECT ANSWER: The imprinted gene is the
silent gene of a gene pair.
What is the primary reason that some older adults have impaired inflammation and
wound healing?
The circulatory system cannot adequately perfuse tissues.
, The underlying chronic illness exists.
The complement is deficient.
The number of mast cells is insufficient. - CORRECT ANSWER: The underlying chronic
illness exists.
A generalized inflammatory response seen in chronic illness depletes the body's
reserves to fight against illness.
Which cells are the body's primary defense against parasite invasion?
B lymphocytes
Eosinophils
Neutrophils
T lymphocytes - CORRECT ANSWER: Eosinophils are the body's primary defense
against parasites.
What Phagocytes bacteria?
eosinophils
macrophages
perforin - CORRECT ANSWER: Macrophages work by eating or phagocytosing
bacteria.
What is the first response to a foreign pathogen?
cytotoxic T
helper T cells
phagocytic - CORRECT ANSWER: Helper T cells
Which characteristic is the most important determinant of immunogenicity when
considering the antigen?
Foreignness
Quantity
