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 TOGETHE R
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? 1 / 4
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.
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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. 3 / 4
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
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