BIOD 151 Anatomy and Physiology I Official
Practice Exam Actual Exam 2026/2027 with
Detailed Rationales | Complete Exam-Style
Questions | Pass Guaranteed – A+ Graded
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SECTION 1: CELLS & CELLULAR TRANSPORT Q1 – Q10
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Question 1 of 50
A patient with severe dehydration receives an IV of pure distilled water. A nurse notices the
patient's red blood cells begin to swell and burst.
A. The distilled water is hypertonic to the cytosol, causing water to leave the cells through
osmosis.
B. The distilled water is hypotonic to the cytosol, causing water to enter the cells through
osmosis. ✓ CORRECT
C. The distilled water is isotonic to the cytosol, so no net water movement occurs across the
membrane.
D. The distilled water creates a hypertonic environment, triggering active transport of water
inward.
Correct Answer: B
Rationale: Distilled water contains no solutes, making it hypotonic compared to the cytosol
of red blood cells, so water rushes in via osmosis and causes hemolysis. Option A
incorrectly states the water is hypertonic, which would cause crenation instead of swelling.
Clinicians always use isotonic saline to avoid destroying red blood cells during fluid
resuscitation.
Question 2 of 50
A laboratory technician treats living cells with a drug that blocks all ATP production. After
treatment, glucose still enters the cells but sodium ions accumulate outside the membrane.
A. Glucose moves by primary active transport, which does not require ATP.
B. Sodium ions normally enter the cell by facilitated diffusion and now cannot exit.
C. Both glucose and sodium use the same carrier protein, which is broken by the drug.
,D. Glucose enters by facilitated diffusion, while sodium is pumped out by the Na⁺/K⁺-ATPase
that requires ATP. ✓ CORRECT
Correct Answer: D
Rationale: Facilitated diffusion moves glucose down its concentration gradient without
energy, whereas the sodium-potassium pump uses ATP to push sodium out against its
gradient. Option B is tempting because it names real transport proteins, but it reverses the
normal direction of sodium movement across the plasma membrane. This distinction
explains why cells swell and burst when ATP is depleted during ischemia.
Question 3 of 50
During a liver biopsy, a pathologist notes abundant smooth endoplasmic reticulum in
hepatocytes from a patient on long-term antiepileptic medication.
A. Smooth ER detoxifies drugs and synthesizes lipids, so its proliferation is an expected
adaptive response. ✓ CORRECT
B. Rough ER increases in response to drug exposure because it houses ribosomes for protein
synthesis.
C. The Golgi apparatus is expanding to package neurotransmitters for enhanced neuronal
signaling.
D. Lysosomes are multiplying to break down the accumulated drug metabolites in liver tissue.
Correct Answer: A
Rationale: Hepatocytes contain abundant smooth ER that contains enzymes for drug
detoxification and lipid synthesis, and chronic drug exposure induces its proliferation. Option
B confuses rough ER, which is studded with ribosomes for protein synthesis, with the
organelle actually responsible for detoxification. This adaptive response is why patients on
chronic medications often require dose adjustments as liver metabolism increases over
time.
Question 4 of 50
A student observes human cheek cells under a microscope and notices a thin boundary that
appears as two dark lines with a light space between them.
A. The student is viewing the glycocalyx, a carbohydrate coat used for cell adhesion.
B. The student is viewing the nuclear envelope, which surrounds the genetic material.
C. The student is viewing the phospholipid bilayer of the plasma membrane. ✓ CORRECT
D. The student is viewing the cytoskeleton, which provides internal structural support.
Correct Answer: C
Rationale: In transmission electron micrographs, the plasma membrane appears as two
electron-dense layers separated by a lighter interior, matching the phospholipid bilayer
, structure. Option A describes the glycocalyx, which is external to the membrane and would
not appear as two distinct lines under standard microscopy. Understanding this trilaminar
appearance helps clinicians interpret electron micrographs of kidney filtration barriers and
skin biopsies.
Question 5 of 50
A cancer researcher examines a tumor sample and finds cells with condensed chromosomes
aligned at the cell's equator and spindle fibers attached to kinetochores.
A. The cells are in prophase, where the nuclear envelope is just beginning to break down.
B. The cells are in metaphase, the checkpoint where chromosome alignment is verified
before separation. ✓ CORRECT
C. The cells are in anaphase, where sister chromatids are being pulled toward opposite poles.
D. The cells are in telophase, where two new nuclear envelopes are reforming around
chromosomes.
Correct Answer: B
Rationale: Metaphase is defined by the alignment of chromosomes at the metaphase plate
with spindle fibers attached to kinetochores, creating the classic equatorial pattern. Option C
describes anaphase, which occurs immediately after metaphase when cohesin proteins are
cleaved and chromatids separate. Oncologists use drugs like taxanes that arrest cells in
metaphase to prevent uncontrolled tumor division.
Question 6 of 50
A microbiologist cultures bacteria in a medium containing human insulin mRNA but no
insulin protein is produced.
A. Bacterial cells lack the spliceosomes needed to remove introns from pre-mRNA. ✓
CORRECT
B. Bacterial ribosomes are too small to translate the large insulin polypeptide chain.
C. Bacterial cells cannot perform transcription because they lack a membrane-bound
nucleus.
D. Bacterial cells destroy all foreign mRNA before translation can begin.
Correct Answer: A
Rationale: Human genes contain introns that must be spliced out by spliceosomes before
translation, and bacteria lack these nuclear machinery components, so they produce
nonfunctional proteins from unprocessed human mRNA. Option B is incorrect because
bacterial ribosomes are fully capable of translating proteins of various sizes, as
demonstrated by recombinant insulin production using engineered bacterial DNA rather than
mRNA. This is why genetic engineers use complementary DNA without introns for bacterial
expression systems.
Practice Exam Actual Exam 2026/2027 with
Detailed Rationales | Complete Exam-Style
Questions | Pass Guaranteed – A+ Graded
══════════════════════════════════════
SECTION 1: CELLS & CELLULAR TRANSPORT Q1 – Q10
══════════════════════════════════════
Question 1 of 50
A patient with severe dehydration receives an IV of pure distilled water. A nurse notices the
patient's red blood cells begin to swell and burst.
A. The distilled water is hypertonic to the cytosol, causing water to leave the cells through
osmosis.
B. The distilled water is hypotonic to the cytosol, causing water to enter the cells through
osmosis. ✓ CORRECT
C. The distilled water is isotonic to the cytosol, so no net water movement occurs across the
membrane.
D. The distilled water creates a hypertonic environment, triggering active transport of water
inward.
Correct Answer: B
Rationale: Distilled water contains no solutes, making it hypotonic compared to the cytosol
of red blood cells, so water rushes in via osmosis and causes hemolysis. Option A
incorrectly states the water is hypertonic, which would cause crenation instead of swelling.
Clinicians always use isotonic saline to avoid destroying red blood cells during fluid
resuscitation.
Question 2 of 50
A laboratory technician treats living cells with a drug that blocks all ATP production. After
treatment, glucose still enters the cells but sodium ions accumulate outside the membrane.
A. Glucose moves by primary active transport, which does not require ATP.
B. Sodium ions normally enter the cell by facilitated diffusion and now cannot exit.
C. Both glucose and sodium use the same carrier protein, which is broken by the drug.
,D. Glucose enters by facilitated diffusion, while sodium is pumped out by the Na⁺/K⁺-ATPase
that requires ATP. ✓ CORRECT
Correct Answer: D
Rationale: Facilitated diffusion moves glucose down its concentration gradient without
energy, whereas the sodium-potassium pump uses ATP to push sodium out against its
gradient. Option B is tempting because it names real transport proteins, but it reverses the
normal direction of sodium movement across the plasma membrane. This distinction
explains why cells swell and burst when ATP is depleted during ischemia.
Question 3 of 50
During a liver biopsy, a pathologist notes abundant smooth endoplasmic reticulum in
hepatocytes from a patient on long-term antiepileptic medication.
A. Smooth ER detoxifies drugs and synthesizes lipids, so its proliferation is an expected
adaptive response. ✓ CORRECT
B. Rough ER increases in response to drug exposure because it houses ribosomes for protein
synthesis.
C. The Golgi apparatus is expanding to package neurotransmitters for enhanced neuronal
signaling.
D. Lysosomes are multiplying to break down the accumulated drug metabolites in liver tissue.
Correct Answer: A
Rationale: Hepatocytes contain abundant smooth ER that contains enzymes for drug
detoxification and lipid synthesis, and chronic drug exposure induces its proliferation. Option
B confuses rough ER, which is studded with ribosomes for protein synthesis, with the
organelle actually responsible for detoxification. This adaptive response is why patients on
chronic medications often require dose adjustments as liver metabolism increases over
time.
Question 4 of 50
A student observes human cheek cells under a microscope and notices a thin boundary that
appears as two dark lines with a light space between them.
A. The student is viewing the glycocalyx, a carbohydrate coat used for cell adhesion.
B. The student is viewing the nuclear envelope, which surrounds the genetic material.
C. The student is viewing the phospholipid bilayer of the plasma membrane. ✓ CORRECT
D. The student is viewing the cytoskeleton, which provides internal structural support.
Correct Answer: C
Rationale: In transmission electron micrographs, the plasma membrane appears as two
electron-dense layers separated by a lighter interior, matching the phospholipid bilayer
, structure. Option A describes the glycocalyx, which is external to the membrane and would
not appear as two distinct lines under standard microscopy. Understanding this trilaminar
appearance helps clinicians interpret electron micrographs of kidney filtration barriers and
skin biopsies.
Question 5 of 50
A cancer researcher examines a tumor sample and finds cells with condensed chromosomes
aligned at the cell's equator and spindle fibers attached to kinetochores.
A. The cells are in prophase, where the nuclear envelope is just beginning to break down.
B. The cells are in metaphase, the checkpoint where chromosome alignment is verified
before separation. ✓ CORRECT
C. The cells are in anaphase, where sister chromatids are being pulled toward opposite poles.
D. The cells are in telophase, where two new nuclear envelopes are reforming around
chromosomes.
Correct Answer: B
Rationale: Metaphase is defined by the alignment of chromosomes at the metaphase plate
with spindle fibers attached to kinetochores, creating the classic equatorial pattern. Option C
describes anaphase, which occurs immediately after metaphase when cohesin proteins are
cleaved and chromatids separate. Oncologists use drugs like taxanes that arrest cells in
metaphase to prevent uncontrolled tumor division.
Question 6 of 50
A microbiologist cultures bacteria in a medium containing human insulin mRNA but no
insulin protein is produced.
A. Bacterial cells lack the spliceosomes needed to remove introns from pre-mRNA. ✓
CORRECT
B. Bacterial ribosomes are too small to translate the large insulin polypeptide chain.
C. Bacterial cells cannot perform transcription because they lack a membrane-bound
nucleus.
D. Bacterial cells destroy all foreign mRNA before translation can begin.
Correct Answer: A
Rationale: Human genes contain introns that must be spliced out by spliceosomes before
translation, and bacteria lack these nuclear machinery components, so they produce
nonfunctional proteins from unprocessed human mRNA. Option B is incorrect because
bacterial ribosomes are fully capable of translating proteins of various sizes, as
demonstrated by recombinant insulin production using engineered bacterial DNA rather than
mRNA. This is why genetic engineers use complementary DNA without introns for bacterial
expression systems.
