BIOS 256 Midterm Exam Questions and Answers with
Rationales |
CHAMBERLAIN UNIVERSITY
Question 1. A student is distinguishing closely related structures and processes. Which finding best
identifies gallbladder?
A. it is a muscular sac connected to the biliary tree beneath the liver
B. they are amphipathic molecules synthesized from cholesterol and secreted in bile
C. it receives both oxygenated arterial blood and nutrient-rich portal venous blood
D. bile salts are actively reclaimed mainly in the terminal ileum and return through portal blood
Correct Answer: A. it is a muscular sac connected to the biliary tree beneath the liver
Explanation: The identifying feature is that it is a muscular sac connected to the biliary tree beneath the liver. That
characteristic is consistent with gallbladder and its normal role: stores and concentrates bile between meals and releases
it during fat digestion. The other findings are characteristic of different items and do not identify gallbladder as
precisely.
Question 2. Which result best demonstrates that alimentary canal wall layers is functioning normally?
A. The system demonstrates that it coordinates ingestion, propulsion, mechanical and chemical digestion,
absorption, and defecation.
B. The system demonstrates that it provide a common structural plan for movement, secretion, absorption, support,
and external covering.
C. The system demonstrates that it coordinates much of gastrointestinal motility and secretion locally.
D. The system demonstrates that it lubricates food, begins digestion, protects oral tissues, and helps dissolve
molecules for taste.
Correct Answer: B. The system demonstrates that it provide a common structural plan for movement, secretion,
absorption, support, and external covering.
Explanation: The strongest evidence is the outcome linked to the normal role of alimentary canal wall layers: provide a
common structural plan for movement, secretion, absorption, support, and external covering. This expected result
depends on the mechanism that specialized epithelial, connective, neural, and smooth-muscle components allow each
segment to perform local functions. The other outcomes would point to different physiologic functions rather than intact
alimentary canal wall layers activity.
Question 3. Which effect would most directly accompany severe disruption of fed-state insulin signaling?
A. ATP output would fall sharply in oxygen-deprived cells that depend heavily on mitochondria
B. postprandial glucose would remain higher and storage responses would be reduced if insulin action were absent
C. ammonia would accumulate dangerously if hepatic urea synthesis failed
D. maintenance of blood glucose during fasting would be more difficult if glucagon action were blocked
Correct Answer: B. postprandial glucose would remain higher and storage responses would be reduced if insulin
action were absent
Explanation: The most direct consequence is that postprandial glucose would remain higher and storage responses would
be reduced if insulin action were absent. That prediction follows because fed-state insulin signaling normally has this
role: promotes storage and use of abundant nutrients after a meal. The distractors reflect dysfunction of other structures
or processes rather than the most direct consequence here.
,Question 4. Which feature is most characteristic of enterohepatic circulation?
A. they are amphipathic molecules synthesized from cholesterol and secreted in bile
B. it is a muscular sac connected to the biliary tree beneath the liver
C. it receives both oxygenated arterial blood and nutrient-rich portal venous blood
D. bile salts are actively reclaimed mainly in the terminal ileum and return through portal blood
Correct Answer: D. bile salts are actively reclaimed mainly in the terminal ileum and return through portal
blood
Explanation: The identifying feature is that bile salts are actively reclaimed mainly in the terminal ileum and return
through portal blood. That characteristic is consistent with enterohepatic circulation and its normal role: recycles most
bile salts from the intestine back to the liver. The other findings are characteristic of different items and do not identify
enterohepatic circulation as precisely.
Question 5. Which mechanism best explains the normal physiology of beta oxidation?
A. energy-dependent reactions bypass irreversible glycolytic steps to create glucose
B. repeated oxidation cycles remove two-carbon fragments while producing NADH and FADH2
C. the liver converts excess acetyl-CoA into acetoacetate and related molecules that other tissues can oxidize
D. glucagon in liver and epinephrine in liver or muscle stimulate enzymes that cleave glycogen
Correct Answer: B. repeated oxidation cycles remove two-carbon fragments while producing NADH and FADH2
Explanation: The correct mechanism is that repeated oxidation cycles remove two-carbon fragments while producing
NADH and FADH2. It explains the normal function of beta oxidation: breaks fatty acids into acetyl-CoA units for
energy metabolism. The other mechanisms belong to different structures or processes in the same broad system.
Question 6. Which option gives an internally consistent description of hepatic portal circulation?
A. It delivers absorbed water-soluble nutrients from the gastrointestinal tract to the liver before systemic
distribution; this is enabled because first-pass hepatic processing allows storage, metabolism, and detoxification
before blood returns to the general circulation.
B. It delivers absorbed water-soluble nutrients from the gastrointestinal tract to the liver before systemic
distribution; this is enabled because intestinal bacteria convert bilirubin derivatives into pigments that contribute to
stool and urine color.
C. It delivers absorbed water-soluble nutrients from the gastrointestinal tract to the liver before systemic
distribution; this is enabled because blood flows from portal triads through sinusoids toward the central vein while
bile moves in the opposite direction through canaliculi.
D. It delivers absorbed water-soluble nutrients from the gastrointestinal tract to the liver before systemic
distribution; this is enabled because amylase, lipase, nucleases, and protease precursors act after entering the
duodenum.
Correct Answer: A. It delivers absorbed water-soluble nutrients from the gastrointestinal tract to the liver before
systemic distribution; this is enabled because first-pass hepatic processing allows storage, metabolism, and
detoxification before blood returns to the general circulation.
Explanation: The correct pairing links hepatic portal circulation to this role: delivers absorbed water-soluble nutrients
from the gastrointestinal tract to the liver before systemic distribution, and to this mechanism: first-pass hepatic
processing allows storage, metabolism, and detoxification before blood returns to the general circulation. A correct
function paired with the wrong mechanism is still an incorrect description. The other options deliberately mix the role of
hepatic portal circulation with mechanisms that belong to different components.
,Question 7. Which effect would most directly accompany severe disruption of renal blood flow?
A. filtration and tubular reabsorption would both be compromised if renal perfusion fell severely
B. the kidney could not regulate plasma composition effectively if large numbers of nephrons were lost
C. an organ found within the peritoneal cavity would not match normal kidney position
D. normal nephron organization would be disrupted by extensive destruction of either region
Correct Answer: A. filtration and tubular reabsorption would both be compromised if renal perfusion fell
severely
Explanation: The most direct consequence is that filtration and tubular reabsorption would both be compromised if renal
perfusion fell severely. That prediction follows because renal blood flow normally has this role: delivers a large fraction
of cardiac output to the kidneys for filtration and regulation. The distractors reflect dysfunction of other structures or
processes rather than the most direct consequence here.
Question 8. The finding 'it acts mainly on principal cells in late distal tubules and collecting ducts' most
specifically points to which item?
A. antidiuretic hormone action
B. thick ascending limb
C. distal convoluted tubule
D. aldosterone action
Correct Answer: D. aldosterone action
Explanation: The description identifies aldosterone action because it acts mainly on principal cells in late distal tubules
and collecting ducts. Its key role is that it promotes sodium reabsorption and potassium secretion in the distal nephron.
The alternative options have different defining features and do not best fit the description.
Question 9. Which change is the most direct prediction when anabolism and catabolism is markedly
abnormal?
A. rapid ATP production from glucose would be impaired if glycolysis stopped
B. deficiency effects depend on which nutrient class and physiologic role are affected
C. energy balance and molecular turnover would fail if cells could perform only one side of metabolism
D. post-meal glucose storage capacity would fall if glycogen synthesis were impaired
Correct Answer: C. energy balance and molecular turnover would fail if cells could perform only one side of
metabolism
Explanation: The most direct consequence is that energy balance and molecular turnover would fail if cells could
perform only one side of metabolism. That prediction follows because anabolism and catabolism normally has this role:
describe the building and breakdown sides of metabolism. The distractors reflect dysfunction of other structures or
processes rather than the most direct consequence here.
, Question 10. Which option gives an internally consistent description of trypsin activation?
A. It initiates a cascade that activates several pancreatic proteases in the small intestine; this is enabled because low
luminal pH triggers secretin release, which promotes neutralization and reduces gastric acid delivery.
B. It initiates a cascade that activates several pancreatic proteases in the small intestine; this is enabled because fatty
acids and amino acids stimulate CCK, which coordinates bile delivery, enzyme secretion, and slower gastric
emptying.
C. It initiates a cascade that activates several pancreatic proteases in the small intestine; this is enabled because
bicarbonate raises duodenal pH, protects mucosa, and creates conditions in which pancreatic enzymes work
effectively.
D. It initiates a cascade that activates several pancreatic proteases in the small intestine; this is enabled because
enteropeptidase activates some trypsinogen, and trypsin then activates additional protease zymogens.
Correct Answer: D. It initiates a cascade that activates several pancreatic proteases in the small intestine; this is
enabled because enteropeptidase activates some trypsinogen, and trypsin then activates additional protease
zymogens.
Explanation: The correct pairing links trypsin activation to this role: initiates a cascade that activates several pancreatic
proteases in the small intestine, and to this mechanism: enteropeptidase activates some trypsinogen, and trypsin then
activates additional protease zymogens. A correct function paired with the wrong mechanism is still an incorrect
description. The other options deliberately mix the role of trypsin activation with mechanisms that belong to different
components.
Question 11. Which combination correctly matches glucose absorption with an identifying feature and a
likely consequence of severe dysfunction?
A. Feature: they are membrane-associated enzymes on small-intestinal microvilli / Dysfunction: glucose absorption
would fall if the sodium gradient across the apical membrane collapsed.
B. Feature: it consists of localized alternating contractions rather than long-distance propulsion / Dysfunction:
glucose absorption would fall if the sodium gradient across the apical membrane collapsed.
C. Feature: apical sodium-glucose cotransport and basolateral facilitated diffusion are major steps / Dysfunction:
glucose absorption would fall if the sodium gradient across the apical membrane collapsed.
D. Feature: it is a cyclic fasting motility pattern that becomes prominent when digestion is not underway /
Dysfunction: glucose absorption would fall if the sodium gradient across the apical membrane collapsed.
Correct Answer: C. Feature: apical sodium-glucose cotransport and basolateral facilitated diffusion are major
steps / Dysfunction: glucose absorption would fall if the sodium gradient across the apical membrane collapsed.
Explanation: For glucose absorption, the identifying feature is that apical sodium-glucose cotransport and basolateral
facilitated diffusion are major steps, and severe dysfunction would mean that glucose absorption would fall if the sodium
gradient across the apical membrane collapsed. Both halves of the pairing must be correct for the option to be valid. The
distractors combine the correct consequence with a defining feature that belongs to another item.
Question 12. A major loss of the physiology represented by fasting-state glucagon signaling would most
likely produce which consequence?
A. ATP output would fall sharply in oxygen-deprived cells that depend heavily on mitochondria
B. maintenance of blood glucose during fasting would be more difficult if glucagon action were blocked
C. ammonia would accumulate dangerously if hepatic urea synthesis failed
D. postprandial glucose would remain higher and storage responses would be reduced if insulin action were absent
Correct Answer: B. maintenance of blood glucose during fasting would be more difficult if glucagon action were
blocked
Explanation: The most direct consequence is that maintenance of blood glucose during fasting would be more difficult if
glucagon action were blocked. That prediction follows because fasting-state glucagon signaling normally has this role:
helps maintain blood glucose and mobilize stored fuels between meals. The distractors reflect dysfunction of other
structures or processes rather than the most direct consequence here.
Rationales |
CHAMBERLAIN UNIVERSITY
Question 1. A student is distinguishing closely related structures and processes. Which finding best
identifies gallbladder?
A. it is a muscular sac connected to the biliary tree beneath the liver
B. they are amphipathic molecules synthesized from cholesterol and secreted in bile
C. it receives both oxygenated arterial blood and nutrient-rich portal venous blood
D. bile salts are actively reclaimed mainly in the terminal ileum and return through portal blood
Correct Answer: A. it is a muscular sac connected to the biliary tree beneath the liver
Explanation: The identifying feature is that it is a muscular sac connected to the biliary tree beneath the liver. That
characteristic is consistent with gallbladder and its normal role: stores and concentrates bile between meals and releases
it during fat digestion. The other findings are characteristic of different items and do not identify gallbladder as
precisely.
Question 2. Which result best demonstrates that alimentary canal wall layers is functioning normally?
A. The system demonstrates that it coordinates ingestion, propulsion, mechanical and chemical digestion,
absorption, and defecation.
B. The system demonstrates that it provide a common structural plan for movement, secretion, absorption, support,
and external covering.
C. The system demonstrates that it coordinates much of gastrointestinal motility and secretion locally.
D. The system demonstrates that it lubricates food, begins digestion, protects oral tissues, and helps dissolve
molecules for taste.
Correct Answer: B. The system demonstrates that it provide a common structural plan for movement, secretion,
absorption, support, and external covering.
Explanation: The strongest evidence is the outcome linked to the normal role of alimentary canal wall layers: provide a
common structural plan for movement, secretion, absorption, support, and external covering. This expected result
depends on the mechanism that specialized epithelial, connective, neural, and smooth-muscle components allow each
segment to perform local functions. The other outcomes would point to different physiologic functions rather than intact
alimentary canal wall layers activity.
Question 3. Which effect would most directly accompany severe disruption of fed-state insulin signaling?
A. ATP output would fall sharply in oxygen-deprived cells that depend heavily on mitochondria
B. postprandial glucose would remain higher and storage responses would be reduced if insulin action were absent
C. ammonia would accumulate dangerously if hepatic urea synthesis failed
D. maintenance of blood glucose during fasting would be more difficult if glucagon action were blocked
Correct Answer: B. postprandial glucose would remain higher and storage responses would be reduced if insulin
action were absent
Explanation: The most direct consequence is that postprandial glucose would remain higher and storage responses would
be reduced if insulin action were absent. That prediction follows because fed-state insulin signaling normally has this
role: promotes storage and use of abundant nutrients after a meal. The distractors reflect dysfunction of other structures
or processes rather than the most direct consequence here.
,Question 4. Which feature is most characteristic of enterohepatic circulation?
A. they are amphipathic molecules synthesized from cholesterol and secreted in bile
B. it is a muscular sac connected to the biliary tree beneath the liver
C. it receives both oxygenated arterial blood and nutrient-rich portal venous blood
D. bile salts are actively reclaimed mainly in the terminal ileum and return through portal blood
Correct Answer: D. bile salts are actively reclaimed mainly in the terminal ileum and return through portal
blood
Explanation: The identifying feature is that bile salts are actively reclaimed mainly in the terminal ileum and return
through portal blood. That characteristic is consistent with enterohepatic circulation and its normal role: recycles most
bile salts from the intestine back to the liver. The other findings are characteristic of different items and do not identify
enterohepatic circulation as precisely.
Question 5. Which mechanism best explains the normal physiology of beta oxidation?
A. energy-dependent reactions bypass irreversible glycolytic steps to create glucose
B. repeated oxidation cycles remove two-carbon fragments while producing NADH and FADH2
C. the liver converts excess acetyl-CoA into acetoacetate and related molecules that other tissues can oxidize
D. glucagon in liver and epinephrine in liver or muscle stimulate enzymes that cleave glycogen
Correct Answer: B. repeated oxidation cycles remove two-carbon fragments while producing NADH and FADH2
Explanation: The correct mechanism is that repeated oxidation cycles remove two-carbon fragments while producing
NADH and FADH2. It explains the normal function of beta oxidation: breaks fatty acids into acetyl-CoA units for
energy metabolism. The other mechanisms belong to different structures or processes in the same broad system.
Question 6. Which option gives an internally consistent description of hepatic portal circulation?
A. It delivers absorbed water-soluble nutrients from the gastrointestinal tract to the liver before systemic
distribution; this is enabled because first-pass hepatic processing allows storage, metabolism, and detoxification
before blood returns to the general circulation.
B. It delivers absorbed water-soluble nutrients from the gastrointestinal tract to the liver before systemic
distribution; this is enabled because intestinal bacteria convert bilirubin derivatives into pigments that contribute to
stool and urine color.
C. It delivers absorbed water-soluble nutrients from the gastrointestinal tract to the liver before systemic
distribution; this is enabled because blood flows from portal triads through sinusoids toward the central vein while
bile moves in the opposite direction through canaliculi.
D. It delivers absorbed water-soluble nutrients from the gastrointestinal tract to the liver before systemic
distribution; this is enabled because amylase, lipase, nucleases, and protease precursors act after entering the
duodenum.
Correct Answer: A. It delivers absorbed water-soluble nutrients from the gastrointestinal tract to the liver before
systemic distribution; this is enabled because first-pass hepatic processing allows storage, metabolism, and
detoxification before blood returns to the general circulation.
Explanation: The correct pairing links hepatic portal circulation to this role: delivers absorbed water-soluble nutrients
from the gastrointestinal tract to the liver before systemic distribution, and to this mechanism: first-pass hepatic
processing allows storage, metabolism, and detoxification before blood returns to the general circulation. A correct
function paired with the wrong mechanism is still an incorrect description. The other options deliberately mix the role of
hepatic portal circulation with mechanisms that belong to different components.
,Question 7. Which effect would most directly accompany severe disruption of renal blood flow?
A. filtration and tubular reabsorption would both be compromised if renal perfusion fell severely
B. the kidney could not regulate plasma composition effectively if large numbers of nephrons were lost
C. an organ found within the peritoneal cavity would not match normal kidney position
D. normal nephron organization would be disrupted by extensive destruction of either region
Correct Answer: A. filtration and tubular reabsorption would both be compromised if renal perfusion fell
severely
Explanation: The most direct consequence is that filtration and tubular reabsorption would both be compromised if renal
perfusion fell severely. That prediction follows because renal blood flow normally has this role: delivers a large fraction
of cardiac output to the kidneys for filtration and regulation. The distractors reflect dysfunction of other structures or
processes rather than the most direct consequence here.
Question 8. The finding 'it acts mainly on principal cells in late distal tubules and collecting ducts' most
specifically points to which item?
A. antidiuretic hormone action
B. thick ascending limb
C. distal convoluted tubule
D. aldosterone action
Correct Answer: D. aldosterone action
Explanation: The description identifies aldosterone action because it acts mainly on principal cells in late distal tubules
and collecting ducts. Its key role is that it promotes sodium reabsorption and potassium secretion in the distal nephron.
The alternative options have different defining features and do not best fit the description.
Question 9. Which change is the most direct prediction when anabolism and catabolism is markedly
abnormal?
A. rapid ATP production from glucose would be impaired if glycolysis stopped
B. deficiency effects depend on which nutrient class and physiologic role are affected
C. energy balance and molecular turnover would fail if cells could perform only one side of metabolism
D. post-meal glucose storage capacity would fall if glycogen synthesis were impaired
Correct Answer: C. energy balance and molecular turnover would fail if cells could perform only one side of
metabolism
Explanation: The most direct consequence is that energy balance and molecular turnover would fail if cells could
perform only one side of metabolism. That prediction follows because anabolism and catabolism normally has this role:
describe the building and breakdown sides of metabolism. The distractors reflect dysfunction of other structures or
processes rather than the most direct consequence here.
, Question 10. Which option gives an internally consistent description of trypsin activation?
A. It initiates a cascade that activates several pancreatic proteases in the small intestine; this is enabled because low
luminal pH triggers secretin release, which promotes neutralization and reduces gastric acid delivery.
B. It initiates a cascade that activates several pancreatic proteases in the small intestine; this is enabled because fatty
acids and amino acids stimulate CCK, which coordinates bile delivery, enzyme secretion, and slower gastric
emptying.
C. It initiates a cascade that activates several pancreatic proteases in the small intestine; this is enabled because
bicarbonate raises duodenal pH, protects mucosa, and creates conditions in which pancreatic enzymes work
effectively.
D. It initiates a cascade that activates several pancreatic proteases in the small intestine; this is enabled because
enteropeptidase activates some trypsinogen, and trypsin then activates additional protease zymogens.
Correct Answer: D. It initiates a cascade that activates several pancreatic proteases in the small intestine; this is
enabled because enteropeptidase activates some trypsinogen, and trypsin then activates additional protease
zymogens.
Explanation: The correct pairing links trypsin activation to this role: initiates a cascade that activates several pancreatic
proteases in the small intestine, and to this mechanism: enteropeptidase activates some trypsinogen, and trypsin then
activates additional protease zymogens. A correct function paired with the wrong mechanism is still an incorrect
description. The other options deliberately mix the role of trypsin activation with mechanisms that belong to different
components.
Question 11. Which combination correctly matches glucose absorption with an identifying feature and a
likely consequence of severe dysfunction?
A. Feature: they are membrane-associated enzymes on small-intestinal microvilli / Dysfunction: glucose absorption
would fall if the sodium gradient across the apical membrane collapsed.
B. Feature: it consists of localized alternating contractions rather than long-distance propulsion / Dysfunction:
glucose absorption would fall if the sodium gradient across the apical membrane collapsed.
C. Feature: apical sodium-glucose cotransport and basolateral facilitated diffusion are major steps / Dysfunction:
glucose absorption would fall if the sodium gradient across the apical membrane collapsed.
D. Feature: it is a cyclic fasting motility pattern that becomes prominent when digestion is not underway /
Dysfunction: glucose absorption would fall if the sodium gradient across the apical membrane collapsed.
Correct Answer: C. Feature: apical sodium-glucose cotransport and basolateral facilitated diffusion are major
steps / Dysfunction: glucose absorption would fall if the sodium gradient across the apical membrane collapsed.
Explanation: For glucose absorption, the identifying feature is that apical sodium-glucose cotransport and basolateral
facilitated diffusion are major steps, and severe dysfunction would mean that glucose absorption would fall if the sodium
gradient across the apical membrane collapsed. Both halves of the pairing must be correct for the option to be valid. The
distractors combine the correct consequence with a defining feature that belongs to another item.
Question 12. A major loss of the physiology represented by fasting-state glucagon signaling would most
likely produce which consequence?
A. ATP output would fall sharply in oxygen-deprived cells that depend heavily on mitochondria
B. maintenance of blood glucose during fasting would be more difficult if glucagon action were blocked
C. ammonia would accumulate dangerously if hepatic urea synthesis failed
D. postprandial glucose would remain higher and storage responses would be reduced if insulin action were absent
Correct Answer: B. maintenance of blood glucose during fasting would be more difficult if glucagon action were
blocked
Explanation: The most direct consequence is that maintenance of blood glucose during fasting would be more difficult if
glucagon action were blocked. That prediction follows because fasting-state glucagon signaling normally has this role:
helps maintain blood glucose and mobilize stored fuels between meals. The distractors reflect dysfunction of other
structures or processes rather than the most direct consequence here.
