WGU D115 ADVANCED PATHOPHYSIOLOGY EXAM QUESTIONS
WITH VERIFIED SOLUTIONS - UPDATED VERSION -
COMPREHENSIVE REVIEW 2026/2027
1. What is the primary difference between reversible and
irreversible cellular injury? ANSWER Reversible injury allows the cell
to recover if the stressor is removed; irreversible injury leads to cell death
(necrosis or apoptosis) due to severe damage to membranes,
mitochondria, or DNA.
2. What are the four main types of cellular adaptation? ANSWER
Hypertrophy, hyperplasia, atrophy, and metaplasia.
3. Define hypertrophy and give an example. ANSWER Hypertrophy is
an increase in cell size leading to increased organ size. Example: cardiac
muscle enlargement due to hypertension.
4. Define hyperplasia and give an example. ANSWER Hyperplasia is
an increase in the number of cells. Example: endometrial thickening
during the menstrual cycle.
5. What is the difference between physiologic and pathologic
atrophy? ANSWER Physiologic atrophy occurs normally (e.g., thymus
involution after puberty); pathologic atrophy results from disease or
decreased workload (e.g., muscle atrophy from immobilization).
6. What is metaplasia, and why is it significant clinically? ANSWER
Metaplasia is the replacement of one differentiated cell type with another.
It is significant because it can be a precursor to dysplasia and cancer (e.g.,
Barrett's esophagus).
7. What is dysplasia? ANSWER Dysplasia is disordered, defective cell
growth with loss of uniformity and architectural orientation; it is often
pre-neoplastic.
8. What are the three main mechanisms of cellular injury? ANSWER
ATP depletion, oxidative stress (free radical damage), and increased
intracellular calcium.
,9. What role do free radicals play in cellular injury? ANSWER Free
radicals are highly reactive molecules that damage lipids, proteins, and
DNA, leading to membrane dysfunction and cell death.
10. What is the most common cause of ATP depletion in cells?
ANSWER Ischemia (inadequate blood supply) and hypoxia (lack of
oxygen).
11. What is apoptosis, and how does it differ from necrosis?
ANSWER Apoptosis is programmed, energy-dependent cell death that is
controlled and does not cause inflammation. Necrosis is accidental,
unregulated cell death caused by injury that triggers inflammation.
12. What are the morphological characteristics of necrosis? ANSWER
Cell swelling, loss of membrane integrity, organelle breakdown, and
nuclear changes (pyknosis, karyorrhexis, karyolysis).
13. What are the five types of necrosis? ANSWER Coagulative,
liquefactive, caseous, fat, and gangrenous necrosis.
14. Which type of necrosis is most characteristic of ischemic injury in
the heart? ANSWER Coagulative necrosis.
15. Which type of necrosis is associated with brain infarcts?
ANSWER Liquefactive necrosis.
16. What is caseous necrosis, and what disease is it associated with?
ANSWER Caseous necrosis is "cheese-like" necrosis associated with
tuberculosis.
17. What is gangrene, and what are its types? ANSWER Gangrene is
necrosis of tissue due to ischemia. Types: dry gangrene (coagulative), wet
gangrene (liquefactive with bacterial infection), and gas gangrene
(clostridial infection).
18. What is the role of p53 in cellular injury? ANSWER p53 is a
tumor suppressor gene that detects DNA damage and either initiates cell
cycle arrest for repair or triggers apoptosis if damage is irreparable.
19. What is the difference between heterozygous and homozygous
genotypes? ANSWER Heterozygous means having two different alleles
for a gene; homozygous means having two identical alleles.
, 20. What is a frameshift mutation? ANSWER A mutation caused by
insertions or deletions of nucleotides that shifts the reading frame,
altering all downstream amino acids.
21. What is a point mutation? ANSWER A mutation affecting a single
nucleotide, which may be silent, missense, or nonsense.
22. What is a missense mutation? ANSWER A point mutation that
results in a different amino acid being incorporated into the protein.
23. What is a nonsense mutation? ANSWER A point mutation that
creates a premature stop codon, resulting in a truncated protein.
24. What is aneuploidy? ANSWER An abnormal number of
chromosomes (either extra or missing), such as trisomy 21 (Down
syndrome).
25. What is the difference between a genotype and a phenotype?
ANSWER Genotype is the genetic makeup; phenotype is the observable
expression of the genotype.
26. What is penetrance? ANSWER The percentage of individuals with a
specific genotype who actually express the associated phenotype.
27. What is expressivity? ANSWER The degree to which a genotype is
phenotypically expressed in an individual.
28. What is a dominant genetic disorder? ANSWER A disorder caused
by a mutation in only one allele of a gene (heterozygous state), such as
Huntington's disease.
29. What is a recessive genetic disorder? ANSWER A disorder that
requires mutations in both alleles (homozygous state), such as cystic
fibrosis or sickle cell disease.
30. What is an X-linked disorder? ANSWER A disorder caused by
mutations in genes on the X chromosome, such as hemophilia A and
Duchenne muscular dystrophy.
31. What is incomplete dominance? ANSWER A heterozygous
phenotype that is intermediate between the two homozygous phenotypes
(e.g., sickle cell trait).
32. What is codominance? ANSWER Both alleles are fully expressed in
the heterozygote (e.g., AB blood type).
WITH VERIFIED SOLUTIONS - UPDATED VERSION -
COMPREHENSIVE REVIEW 2026/2027
1. What is the primary difference between reversible and
irreversible cellular injury? ANSWER Reversible injury allows the cell
to recover if the stressor is removed; irreversible injury leads to cell death
(necrosis or apoptosis) due to severe damage to membranes,
mitochondria, or DNA.
2. What are the four main types of cellular adaptation? ANSWER
Hypertrophy, hyperplasia, atrophy, and metaplasia.
3. Define hypertrophy and give an example. ANSWER Hypertrophy is
an increase in cell size leading to increased organ size. Example: cardiac
muscle enlargement due to hypertension.
4. Define hyperplasia and give an example. ANSWER Hyperplasia is
an increase in the number of cells. Example: endometrial thickening
during the menstrual cycle.
5. What is the difference between physiologic and pathologic
atrophy? ANSWER Physiologic atrophy occurs normally (e.g., thymus
involution after puberty); pathologic atrophy results from disease or
decreased workload (e.g., muscle atrophy from immobilization).
6. What is metaplasia, and why is it significant clinically? ANSWER
Metaplasia is the replacement of one differentiated cell type with another.
It is significant because it can be a precursor to dysplasia and cancer (e.g.,
Barrett's esophagus).
7. What is dysplasia? ANSWER Dysplasia is disordered, defective cell
growth with loss of uniformity and architectural orientation; it is often
pre-neoplastic.
8. What are the three main mechanisms of cellular injury? ANSWER
ATP depletion, oxidative stress (free radical damage), and increased
intracellular calcium.
,9. What role do free radicals play in cellular injury? ANSWER Free
radicals are highly reactive molecules that damage lipids, proteins, and
DNA, leading to membrane dysfunction and cell death.
10. What is the most common cause of ATP depletion in cells?
ANSWER Ischemia (inadequate blood supply) and hypoxia (lack of
oxygen).
11. What is apoptosis, and how does it differ from necrosis?
ANSWER Apoptosis is programmed, energy-dependent cell death that is
controlled and does not cause inflammation. Necrosis is accidental,
unregulated cell death caused by injury that triggers inflammation.
12. What are the morphological characteristics of necrosis? ANSWER
Cell swelling, loss of membrane integrity, organelle breakdown, and
nuclear changes (pyknosis, karyorrhexis, karyolysis).
13. What are the five types of necrosis? ANSWER Coagulative,
liquefactive, caseous, fat, and gangrenous necrosis.
14. Which type of necrosis is most characteristic of ischemic injury in
the heart? ANSWER Coagulative necrosis.
15. Which type of necrosis is associated with brain infarcts?
ANSWER Liquefactive necrosis.
16. What is caseous necrosis, and what disease is it associated with?
ANSWER Caseous necrosis is "cheese-like" necrosis associated with
tuberculosis.
17. What is gangrene, and what are its types? ANSWER Gangrene is
necrosis of tissue due to ischemia. Types: dry gangrene (coagulative), wet
gangrene (liquefactive with bacterial infection), and gas gangrene
(clostridial infection).
18. What is the role of p53 in cellular injury? ANSWER p53 is a
tumor suppressor gene that detects DNA damage and either initiates cell
cycle arrest for repair or triggers apoptosis if damage is irreparable.
19. What is the difference between heterozygous and homozygous
genotypes? ANSWER Heterozygous means having two different alleles
for a gene; homozygous means having two identical alleles.
, 20. What is a frameshift mutation? ANSWER A mutation caused by
insertions or deletions of nucleotides that shifts the reading frame,
altering all downstream amino acids.
21. What is a point mutation? ANSWER A mutation affecting a single
nucleotide, which may be silent, missense, or nonsense.
22. What is a missense mutation? ANSWER A point mutation that
results in a different amino acid being incorporated into the protein.
23. What is a nonsense mutation? ANSWER A point mutation that
creates a premature stop codon, resulting in a truncated protein.
24. What is aneuploidy? ANSWER An abnormal number of
chromosomes (either extra or missing), such as trisomy 21 (Down
syndrome).
25. What is the difference between a genotype and a phenotype?
ANSWER Genotype is the genetic makeup; phenotype is the observable
expression of the genotype.
26. What is penetrance? ANSWER The percentage of individuals with a
specific genotype who actually express the associated phenotype.
27. What is expressivity? ANSWER The degree to which a genotype is
phenotypically expressed in an individual.
28. What is a dominant genetic disorder? ANSWER A disorder caused
by a mutation in only one allele of a gene (heterozygous state), such as
Huntington's disease.
29. What is a recessive genetic disorder? ANSWER A disorder that
requires mutations in both alleles (homozygous state), such as cystic
fibrosis or sickle cell disease.
30. What is an X-linked disorder? ANSWER A disorder caused by
mutations in genes on the X chromosome, such as hemophilia A and
Duchenne muscular dystrophy.
31. What is incomplete dominance? ANSWER A heterozygous
phenotype that is intermediate between the two homozygous phenotypes
(e.g., sickle cell trait).
32. What is codominance? ANSWER Both alleles are fully expressed in
the heterozygote (e.g., AB blood type).
