WGU D115 Advanced Pathophysiology
Exam 2025 – Verified Test Bank with
Practice Exam, Detailed Rationales &
Study Guide
Below is a comprehensive set of 200 original multiple-choice questions designed to align
with the WGU D115 Advanced Pathophysiology curriculum for 2025. Each question
includes four answer options, with the correct answer highlighted in blue, followed by a
detailed expert rationale that reflects the depth and specificity expected in the WGU
curriculum. The questions cover key pathophysiological concepts, including cellular
adaptations, genetics, immune responses, cardiovascular, respiratory, gastrointestinal,
renal, neurological, endocrine, hematologic, and musculoskeletal systems, among others, to
ensure thorough preparation for the exam.
Unit 1: Cellular Function and Genetics
1. Which cellular adaptation is characterized by an increase in cell size due to
increased workload?
o A) Atrophy
o B) Hyperplasia
o C) Hypertrophy
o D) Metaplasia
Rationale: Hypertrophy is the increase in cell size due to increased workload or stress, such as in
cardiac muscle cells in response to hypertension. Atrophy involves cell shrinkage, hyperplasia is
an increase in cell number, and metaplasia is a change in cell type. This aligns with WGU’s
focus on cellular responses to stress.
2. What is the primary role of apoptosis in maintaining cellular homeostasis?
o A) Increase cell proliferation
o B) Programmed cell death
o C) Promote inflammation
o D) Enhance cell growth
Rationale: Apoptosis is a programmed process of cell death that eliminates damaged or
unnecessary cells to maintain tissue homeostasis. It is tightly regulated and does not induce
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inflammation, unlike necrosis. This concept is critical in understanding cellular balance in
pathophysiology.
3. A patient with a genetic disorder has a mutation in a single gene. Which term
describes this condition?
o A) Chromosomal aberration
o B) Monogenic disorder
o C) Polygenic disorder
o D) Multifactorial inheritance
Rationale: A monogenic disorder results from a mutation in a single gene, such as cystic
fibrosis. Chromosomal aberrations involve structural or numerical chromosome changes,
polygenic disorders involve multiple genes, and multifactorial inheritance includes genetic and
environmental factors.
4. Which type of genetic mutation is most likely to result in a nonfunctional protein?
o A) Silent mutation
o B) Missense mutation
o C) Nonsense mutation
o D) Frameshift mutation
Rationale: A nonsense mutation introduces a premature stop codon, leading to a truncated,
nonfunctional protein. Silent mutations do not alter the protein, missense mutations change one
amino acid, and frameshift mutations disrupt the reading frame, but nonsense mutations are more
likely to render the protein nonfunctional.
5. What is the primary source of oxidative stress in cells?
o A) Excessive protein synthesis
o B) Reactive oxygen species
o C) Mitochondrial DNA replication
o D) Lysosomal enzyme activity
Rationale: Reactive oxygen species (ROS), such as free radicals, cause oxidative stress by
damaging cellular components like DNA, proteins, and lipids. This is a key mechanism in
cellular injury and aging, emphasized in the WGU curriculum.
6. Which cellular structure is most affected in mitochondrial disorders?
o A) Nucleus
o B) Mitochondria
o C) Endoplasmic reticulum
o D) Golgi apparatus
Rationale: Mitochondrial disorders primarily affect mitochondria, the organelles responsible for
ATP production. Mutations in mitochondrial DNA or nuclear genes encoding mitochondrial
proteins impair energy production, leading to multi-system dysfunction.
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7. A patient with Down syndrome most likely has which genetic abnormality?
o A) Monosomy 21
o B) Trisomy 21
o C) Deletion of chromosome 21
o D) Translocation of chromosome 15
Rationale: Down syndrome is caused by trisomy 21, where an extra copy of chromosome 21
leads to characteristic physical and cognitive features. Monosomy involves loss of a
chromosome, deletion affects part of a chromosome, and translocation involves chromosome
rearrangement.
8. Which process describes the replacement of one mature cell type with another?
o A) Hyperplasia
o B) Dysplasia
o C) Metaplasia
o D) Anaplasia
Rationale: Metaplasia is the reversible replacement of one differentiated cell type with another,
often as an adaptive response to stress (e.g., squamous metaplasia in smokers’ airways).
Hyperplasia increases cell number, dysplasia involves abnormal cell growth, and anaplasia
indicates dedifferentiation.
9. What is the primary cause of cellular injury in hypoxia?
o A) Excessive calcium influx
o B) Decreased ATP production
o C) Increased protein synthesis
o D) Lysosomal rupture
Rationale: Hypoxia reduces oxygen availability, impairing mitochondrial ATP production via
oxidative phosphorylation. This energy deficit disrupts cellular functions, leading to injury.
Other mechanisms like calcium influx may occur secondarily.
10. Which genetic disorder is characterized by a trinucleotide repeat expansion?
o A) Cystic fibrosis
o B) Huntington’s disease
o C) Sickle cell anemia
o D) Hemophilia
Rationale: Huntington’s disease is caused by a trinucleotide (CAG) repeat expansion in the
huntingtin gene, leading to neuronal degeneration. Cystic fibrosis and sickle cell anemia result
from point mutations, and hemophilia is due to mutations in clotting factor genes.
Unit 2: Immune System and Inflammation
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11. What is the primary role of cytokines in the inflammatory response?
o A) Mediate cell signaling
o B) Directly destroy pathogens
o C) Inhibit immune cell migration
o D) Reduce blood flow to tissues
Rationale: Cytokines are signaling molecules that coordinate immune responses by promoting
inflammation, recruiting immune cells, and regulating immune activity. They do not directly
destroy pathogens or inhibit immune responses.
12. Which type of hypersensitivity reaction is associated with anaphylaxis?
o A) Type II
o B) Type I
o C) Type III
o D) Type IV
Rationale: Type I hypersensitivity is an IgE-mediated immediate reaction, as seen in
anaphylaxis, triggered by allergens. Type II involves cytotoxic antibodies, Type III involves
immune complexes, and Type IV is delayed and T-cell mediated.
13. A patient with systemic lupus erythematosus (SLE) likely has which type of immune
dysfunction?
o A) Autoimmune
o B) Immunodeficiency
o C) Hypersensitivity
o D) Allergic
Rationale: SLE is an autoimmune disorder where the immune system produces autoantibodies
against self-antigens, leading to widespread tissue damage. It is not primarily an
immunodeficiency, hypersensitivity, or allergic condition.
14. What is the hallmark of acute inflammation?
o A) Fibrosis
o B) Neutrophil infiltration
o C) Lymphocyte predominance
o D) Chronic tissue remodeling
Rationale: Acute inflammation is characterized by rapid neutrophil infiltration to the site of
injury or infection, along with vasodilation and edema. Chronic inflammation involves
lymphocytes and tissue remodeling, while fibrosis is a late-stage outcome.
15. Which immunoglobulin is most associated with allergic reactions?
o A) IgG
o B) IgE
o C) IgM
o D) IgA