NR 507 Midterm Exam (2026) – Pathophysiology
Chamberlain University College of Nursing Actual
Questions & Answers with Rationales
Section 1: Cellular Biology and Genetics (Questions 1-35)
1. Which cellular organelle is responsible for ATP production through
oxidative phosphorylation?
A. Ribosome
B. Golgi apparatus
C. Mitochondrion
D. Endoplasmic reticulum
Answer: C. Mitochondrion
Rationale: The mitochondrion is the powerhouse of the cell,
responsible for ATP production through oxidative phosphorylation
via the electron transport chain. This process generates approximately
36 ATP molecules per glucose molecule .
2. A patient is diagnosed with a genetic disorder caused by a mutation in a
single gene. This type of disorder is classified as:
A. Chromosomal disorder
B. Multifactorial disorder
C. Mendelian disorder
D. Mitochondrial disorder
Answer: C. Mendelian disorder
Rationale: Mendelian disorders are caused by mutations in a single
gene and follow predictable inheritance patterns (autosomal
dominant, autosomal recessive, or X-linked). Examples include cystic
fibrosis, Huntington disease, and sickle cell anemia .
3. Which statement best describes the function of the cell membrane?
A. It is a rigid barrier that prevents all substances from entering the cell
,B. It is a selectively permeable barrier that regulates transport of substances
C. It is responsible for protein synthesis
D. It contains digestive enzymes for cellular waste
Answer: B. It is a selectively permeable barrier that regulates transport
of substances
Rationale: The cell membrane is a selectively permeable phospholipid
bilayer that regulates the movement of substances into and out of the
cell through passive and active transport mechanisms .
4. A child is diagnosed with Down syndrome. This condition is caused by:
A. A single gene mutation
B. Trisomy of chromosome 21
C. Deletion of chromosome 5
D. Translocation of chromosome 9 and 22
Answer: B. Trisomy of chromosome 21
Rationale: Down syndrome (trisomy 21) is caused by an extra copy of
chromosome 21, resulting in characteristic physical features,
intellectual disability, and increased risk for congenital heart defects
and Alzheimer disease .
5. Which cellular process is responsible for the programmed death of cells?
A. Necrosis
B. Apoptosis
C. Autophagy
D. Metaplasia
Answer: B. Apoptosis
Rationale: Apoptosis is programmed cell death that occurs in response
to physiologic or pathologic stimuli. It is characterized by cell
shrinkage, chromatin condensation, and formation of apoptotic
bodies without inflammation .
6. A patient with a family history of breast cancer undergoes genetic testing
and is found to have a mutation in the BRCA1 gene. This gene is classified as
,a:
A. Proto-oncogene
B. Tumor suppressor gene
C. Oncogene
D. DNA repair gene
Answer: B. Tumor suppressor gene
Rationale: BRCA1 is a tumor suppressor gene that encodes proteins
involved in DNA repair. Mutations in BRCA1 increase the risk of
breast, ovarian, and other cancers by allowing accumulation of DNA
damage .
7. Which phase of the cell cycle is characterized by DNA replication?
A. G1 phase
B. S phase
C. G2 phase
D. M phase
Answer: B. S phase
Rationale: The S (synthesis) phase is when DNA replication occurs,
resulting in duplication of chromosomes. G1 is cell growth, G2 is
preparation for mitosis, and M phase is mitosis .
8. A 45-year-old male presents with fatigue and pallor. Laboratory studies
reveal macrocytic anemia. Further testing shows elevated homocysteine and
normal methylmalonic acid levels. Which vitamin deficiency is most likely?
A. Vitamin B12 deficiency
B. Folate deficiency
C. Iron deficiency
D. Vitamin D deficiency
Answer: B. Folate deficiency
Rationale: Both vitamin B12 and folate deficiencies cause macrocytic
anemia with elevated homocysteine. However, methylmalonic acid is
elevated only in B12 deficiency. Normal methylmalonic acid with
elevated homocysteine points to folate deficiency .
, 9. Which of the following is an example of a multifactorial disorder?
A. Cystic fibrosis
B. Huntington disease
C. Type 2 diabetes mellitus
D. Hemophilia A
Answer: C. Type 2 diabetes mellitus
Rationale: Multifactorial disorders result from interactions between
multiple genes and environmental factors. Type 2 diabetes,
hypertension, and coronary artery disease are examples. Cystic
fibrosis and Huntington disease are Mendelian; hemophilia A is X-
linked .
10. A patient with chronic alcoholism develops liver disease. On liver biopsy,
hepatocytes are enlarged with accumulation of fat. This cellular adaptation is
called:
A. Hyperplasia
B. Hypertrophy
C. Atrophy
D. Metaplasia
Answer: B. Hypertrophy
Rationale: Hypertrophy is an increase in cell size. In alcoholic liver
disease, hepatocytes undergo hypertrophy and accumulate fat
(steatosis). Hyperplasia is increased cell number; atrophy is decreased
size; metaplasia is replacement of one cell type with another .
11. Which genetic disorder is caused by a trinucleotide repeat expansion?
A. Sickle cell anemia
B. Huntington disease
C. Down syndrome
D. Turner syndrome
Answer: B. Huntington disease
Rationale: Huntington disease is caused by an expanded CAG trinucleotide
repeat in the HTT gene. The number of repeats correlates with age of onset
Chamberlain University College of Nursing Actual
Questions & Answers with Rationales
Section 1: Cellular Biology and Genetics (Questions 1-35)
1. Which cellular organelle is responsible for ATP production through
oxidative phosphorylation?
A. Ribosome
B. Golgi apparatus
C. Mitochondrion
D. Endoplasmic reticulum
Answer: C. Mitochondrion
Rationale: The mitochondrion is the powerhouse of the cell,
responsible for ATP production through oxidative phosphorylation
via the electron transport chain. This process generates approximately
36 ATP molecules per glucose molecule .
2. A patient is diagnosed with a genetic disorder caused by a mutation in a
single gene. This type of disorder is classified as:
A. Chromosomal disorder
B. Multifactorial disorder
C. Mendelian disorder
D. Mitochondrial disorder
Answer: C. Mendelian disorder
Rationale: Mendelian disorders are caused by mutations in a single
gene and follow predictable inheritance patterns (autosomal
dominant, autosomal recessive, or X-linked). Examples include cystic
fibrosis, Huntington disease, and sickle cell anemia .
3. Which statement best describes the function of the cell membrane?
A. It is a rigid barrier that prevents all substances from entering the cell
,B. It is a selectively permeable barrier that regulates transport of substances
C. It is responsible for protein synthesis
D. It contains digestive enzymes for cellular waste
Answer: B. It is a selectively permeable barrier that regulates transport
of substances
Rationale: The cell membrane is a selectively permeable phospholipid
bilayer that regulates the movement of substances into and out of the
cell through passive and active transport mechanisms .
4. A child is diagnosed with Down syndrome. This condition is caused by:
A. A single gene mutation
B. Trisomy of chromosome 21
C. Deletion of chromosome 5
D. Translocation of chromosome 9 and 22
Answer: B. Trisomy of chromosome 21
Rationale: Down syndrome (trisomy 21) is caused by an extra copy of
chromosome 21, resulting in characteristic physical features,
intellectual disability, and increased risk for congenital heart defects
and Alzheimer disease .
5. Which cellular process is responsible for the programmed death of cells?
A. Necrosis
B. Apoptosis
C. Autophagy
D. Metaplasia
Answer: B. Apoptosis
Rationale: Apoptosis is programmed cell death that occurs in response
to physiologic or pathologic stimuli. It is characterized by cell
shrinkage, chromatin condensation, and formation of apoptotic
bodies without inflammation .
6. A patient with a family history of breast cancer undergoes genetic testing
and is found to have a mutation in the BRCA1 gene. This gene is classified as
,a:
A. Proto-oncogene
B. Tumor suppressor gene
C. Oncogene
D. DNA repair gene
Answer: B. Tumor suppressor gene
Rationale: BRCA1 is a tumor suppressor gene that encodes proteins
involved in DNA repair. Mutations in BRCA1 increase the risk of
breast, ovarian, and other cancers by allowing accumulation of DNA
damage .
7. Which phase of the cell cycle is characterized by DNA replication?
A. G1 phase
B. S phase
C. G2 phase
D. M phase
Answer: B. S phase
Rationale: The S (synthesis) phase is when DNA replication occurs,
resulting in duplication of chromosomes. G1 is cell growth, G2 is
preparation for mitosis, and M phase is mitosis .
8. A 45-year-old male presents with fatigue and pallor. Laboratory studies
reveal macrocytic anemia. Further testing shows elevated homocysteine and
normal methylmalonic acid levels. Which vitamin deficiency is most likely?
A. Vitamin B12 deficiency
B. Folate deficiency
C. Iron deficiency
D. Vitamin D deficiency
Answer: B. Folate deficiency
Rationale: Both vitamin B12 and folate deficiencies cause macrocytic
anemia with elevated homocysteine. However, methylmalonic acid is
elevated only in B12 deficiency. Normal methylmalonic acid with
elevated homocysteine points to folate deficiency .
, 9. Which of the following is an example of a multifactorial disorder?
A. Cystic fibrosis
B. Huntington disease
C. Type 2 diabetes mellitus
D. Hemophilia A
Answer: C. Type 2 diabetes mellitus
Rationale: Multifactorial disorders result from interactions between
multiple genes and environmental factors. Type 2 diabetes,
hypertension, and coronary artery disease are examples. Cystic
fibrosis and Huntington disease are Mendelian; hemophilia A is X-
linked .
10. A patient with chronic alcoholism develops liver disease. On liver biopsy,
hepatocytes are enlarged with accumulation of fat. This cellular adaptation is
called:
A. Hyperplasia
B. Hypertrophy
C. Atrophy
D. Metaplasia
Answer: B. Hypertrophy
Rationale: Hypertrophy is an increase in cell size. In alcoholic liver
disease, hepatocytes undergo hypertrophy and accumulate fat
(steatosis). Hyperplasia is increased cell number; atrophy is decreased
size; metaplasia is replacement of one cell type with another .
11. Which genetic disorder is caused by a trinucleotide repeat expansion?
A. Sickle cell anemia
B. Huntington disease
C. Down syndrome
D. Turner syndrome
Answer: B. Huntington disease
Rationale: Huntington disease is caused by an expanded CAG trinucleotide
repeat in the HTT gene. The number of repeats correlates with age of onset
