BIOS 255 Exam 1 Questions and Answers with Rationales |
CHAMBERLAIN UNIVERSITY
Question 1. Which two-part description of reticulocyte is physiologically accurate?
A. It serves as an immature erythrocyte whose abundance reflects recent bone-marrow red-cell output; this is
enabled because its shape increases surface-area-to-volume ratio and flexibility while hemoglobin binds respiratory
gases.
B. It serves as an immature erythrocyte whose abundance reflects recent bone-marrow red-cell output; this is
enabled because newly released erythroid cells complete maturation in the circulation over roughly one to two days.
C. It serves as an immature erythrocyte whose abundance reflects recent bone-marrow red-cell output; this is
enabled because renal oxygen sensing increases erythropoietin secretion, which promotes survival and
differentiation of erythroid precursors.
D. It serves as an immature erythrocyte whose abundance reflects recent bone-marrow red-cell output; this is
enabled because oxygen reversibly binds to iron in heme groups, allowing loading in lungs and unloading in tissues.
Correct Answer: B. It serves as an immature erythrocyte whose abundance reflects recent bone-marrow red-cell
output; this is enabled because newly released erythroid cells complete maturation in the circulation over roughly
one to two days.
Explanation: The correct pairing links reticulocyte to this role: serves as an immature erythrocyte whose abundance
reflects recent bone-marrow red-cell output, and to this mechanism: newly released erythroid cells complete maturation
in the circulation over roughly one to two days. A correct function paired with the wrong mechanism is still an incorrect
description. The other options deliberately mix the role of reticulocyte with mechanisms that belong to different
components.
Question 2. Which change is the most direct prediction when Frank-Starling mechanism is markedly
abnormal?
A. whole-body blood flow would decrease if output fell substantially without compensation
B. cardiac output would fall if heart rate did not increase to compensate
C. heart rate and contractile reserve during increased demand would be reduced
D. the heart would be less able to adjust stroke volume to short-term changes in venous return
Correct Answer: D. the heart would be less able to adjust stroke volume to short-term changes in venous return
Explanation: The most direct consequence is that the heart would be less able to adjust stroke volume to short-term
changes in venous return. That prediction follows because Frank-Starling mechanism normally has this role: matches
ventricular output to venous return by increasing force of contraction as myocardial fibers are stretched within
physiologic limits. The distractors reflect dysfunction of other structures or processes rather than the most direct
consequence here.
Question 3. Which option accurately links a hallmark of basophil with the expected result of major
impairment?
A. Feature: it is a granulocyte with a bilobed nucleus and prominent red-orange granules / Dysfunction: some
immediate inflammatory signaling and hypersensitivity responses would be blunted.
B. Feature: it is the most abundant circulating leukocyte and has a multilobed nucleus with pale granules /
Dysfunction: some immediate inflammatory signaling and hypersensitivity responses would be blunted.
C. Feature: it is typically the largest leukocyte in a blood smear and has a kidney-shaped nucleus / Dysfunction:
some immediate inflammatory signaling and hypersensitivity responses would be blunted.
D. Feature: it is a rare circulating granulocyte whose dark granules may obscure its bilobed nucleus / Dysfunction:
some immediate inflammatory signaling and hypersensitivity responses would be blunted.
Correct Answer: D. Feature: it is a rare circulating granulocyte whose dark granules may obscure its bilobed
nucleus / Dysfunction: some immediate inflammatory signaling and hypersensitivity responses would be blunted.
Explanation: For basophil, the identifying feature is that it is a rare circulating granulocyte whose dark granules may
obscure its bilobed nucleus, and severe dysfunction would mean that some immediate inflammatory signaling and
,hypersensitivity responses would be blunted. 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 4. A learner notes the following feature: it can be calculated as end-diastolic volume minus
end-systolic volume. Which structure or process is being described?
A. Frank-Starling mechanism
B. sympathetic cardiac stimulation
C. stroke volume
D. cardiac output
Correct Answer: C. stroke volume
Explanation: The description identifies stroke volume because it can be calculated as end-diastolic volume minus
end-systolic volume. Its key role is that it represents the volume ejected by one ventricle during a single heartbeat. The
alternative options have different defining features and would not best fit the description.
Question 5. Which two-part description of eosinophil is physiologically accurate?
A. It helps defend against multicellular parasites and participates in allergic inflammation; this is enabled because
granule proteins can damage parasites while mediators modify inflammatory and allergic responses.
B. It helps defend against multicellular parasites and participates in allergic inflammation; this is enabled because
after leaving the bloodstream it differentiates into long-lived tissue phagocytes that ingest debris and pathogens.
C. It helps defend against multicellular parasites and participates in allergic inflammation; this is enabled because
degranulation releases vasoactive and inflammatory mediators, including histamine.
D. It helps defend against multicellular parasites and participates in allergic inflammation; this is enabled because
different lymphocyte subsets recognize antigens, produce antibodies, coordinate immunity, or kill abnormal cells.
Correct Answer: A. It helps defend against multicellular parasites and participates in allergic inflammation; this
is enabled because granule proteins can damage parasites while mediators modify inflammatory and allergic
responses.
Explanation: The correct pairing links eosinophil to this role: helps defend against multicellular parasites and
participates in allergic inflammation, and to this mechanism: granule proteins can damage parasites while mediators
modify inflammatory and allergic responses. A correct function paired with the wrong mechanism is still an incorrect
description. The other options deliberately mix the role of eosinophil with mechanisms that belong to different
components.
Question 6. Which normal function best matches atrioventricular node?
A. rapidly distributes electrical excitation through the ventricles to coordinate ventricular contraction
B. represents atrial depolarization
C. delays conduction from atria to ventricles so ventricular filling can proceed before ventricular depolarization
D. deliver oxygenated blood to the myocardium so cardiac muscle can sustain continuous work
Correct Answer: C. delays conduction from atria to ventricles so ventricular filling can proceed before
ventricular depolarization
Explanation: The correct choice describes this function: delays conduction from atria to ventricles so ventricular filling
can proceed before ventricular depolarization. This is the primary role associated with atrioventricular node, and it is
supported by the mechanism that slow conduction through nodal tissue creates the normal delay before impulses enter
the AV bundle. The other choices describe functions performed by different components within the same course domain.
,Question 7. A patient forms an initial platelet plug, but the plug repeatedly breaks down because fibrin
strands do not develop. Which explanation best accounts for this finding?
A. vascular spasm is the rapid vasoconstrictor phase of hemostasis
B. failure of platelet adhesion disrupts primary hemostasis and plug formation
C. the defect lies in coagulation, which normally stabilizes the plug with fibrin
D. the bleeding pattern reflects impaired platelet plug formation
Correct Answer: C. the defect lies in coagulation, which normally stabilizes the plug with fibrin
Explanation: The best interpretation is that the defect lies in coagulation, which normally stabilizes the plug with fibrin.
This scenario centers on coagulation, whose normal physiologic role is described as follows: stabilizes hemostasis by
generating fibrin strands that reinforce the platelet plug. That relationship is more directly supported by the stated
findings than the alternative explanations.
Question 8. Which effect would most directly accompany severe disruption of coronary arteries?
A. ventricular depolarization would become slower or less coordinated
B. myocardial ischemia and reduced contractile function could develop when flow is severely limited
C. a slower subsidiary pacemaker could take over if this node failed completely
D. atrial impulses would reach the ventricles with abnormal timing or might fail to conduct normally
Correct Answer: B. myocardial ischemia and reduced contractile function could develop when flow is severely
limited
Explanation: The most direct consequence is that myocardial ischemia and reduced contractile function could develop
when flow is severely limited. That prediction follows because coronary arteries normally has this role: deliver
oxygenated blood to the myocardium so cardiac muscle can sustain continuous work. The distractors reflect dysfunction
of other structures or processes rather than the most direct consequence here.
Question 9. Which feature is most characteristic of platelet?
A. it is the earliest local response in hemostasis and occurs before a stable fibrin clot is formed
B. it is a small anucleate cell fragment shed from megakaryocytes
C. its final common pathway produces thrombin, which converts fibrinogen to fibrin
D. it depends strongly on platelet binding to exposed subendothelial structures and to one another
Correct Answer: B. it is a small anucleate cell fragment shed from megakaryocytes
Explanation: The identifying feature is that it is a small anucleate cell fragment shed from megakaryocytes. That
characteristic is consistent with platelet and its normal role: forms the initial platelet plug and provides a phospholipid
surface that supports coagulation reactions. The other findings are characteristic of different items and do not identify
platelet as precisely.
Question 10. Which item matches this identifying characteristic: it is the small deflection that normally
precedes the QRS complex?
A. P wave of the ECG
B. atrioventricular node
C. His-Purkinje conduction system
D. QRS complex of the ECG
Correct Answer: A. P wave of the ECG
Explanation: The description identifies P wave of the ECG because it is the small deflection that normally precedes the
QRS complex. Its key role is that it represents atrial depolarization. The alternative options have different defining
features and would not best fit the description.
, Question 11. Which result best demonstrates that hemoglobin is functioning normally?
A. The system demonstrates that it binds most oxygen carried in blood and participates in buffering and carbon
dioxide transport.
B. The system demonstrates that it transports oxygen and contributes to carbon dioxide transport through
hemoglobin and intracellular enzymes.
C. The system demonstrates that it serves as an immature erythrocyte whose abundance reflects recent
bone-marrow red-cell output.
D. The system demonstrates that it stimulates red bone marrow to increase erythrocyte production when tissue
oxygen availability is low.
Correct Answer: A. The system demonstrates that it binds most oxygen carried in blood and participates in
buffering and carbon dioxide transport.
Explanation: The strongest evidence is the outcome linked to the normal role of hemoglobin: binds most oxygen carried
in blood and participates in buffering and carbon dioxide transport. This expected result depends on the mechanism that
oxygen reversibly binds to iron in heme groups, allowing loading in lungs and unloading in tissues. The other outcomes
would point to different physiologic functions rather than intact hemoglobin activity.
Question 12. A learner notes the following feature: it equals heart rate multiplied by stroke volume.
Which structure or process is being described?
A. Frank-Starling mechanism
B. sympathetic cardiac stimulation
C. stroke volume
D. cardiac output
Correct Answer: D. cardiac output
Explanation: The description identifies cardiac output because it equals heart rate multiplied by stroke volume. Its key
role is that it expresses the volume of blood pumped by one ventricle per minute. The alternative options have different
defining features and would not best fit the description.
Question 13. Which observation would provide the strongest evidence of normal reticulocyte function?
A. The system demonstrates that it transports oxygen and contributes to carbon dioxide transport through
hemoglobin and intracellular enzymes.
B. The system demonstrates that it binds most oxygen carried in blood and participates in buffering and carbon
dioxide transport.
C. The system demonstrates that it serves as an immature erythrocyte whose abundance reflects recent
bone-marrow red-cell output.
D. The system demonstrates that it stimulates red bone marrow to increase erythrocyte production when tissue
oxygen availability is low.
Correct Answer: C. The system demonstrates that it serves as an immature erythrocyte whose abundance
reflects recent bone-marrow red-cell output.
Explanation: The strongest evidence is the outcome linked to the normal role of reticulocyte: serves as an immature
erythrocyte whose abundance reflects recent bone-marrow red-cell output. This expected result depends on the
mechanism that newly released erythroid cells complete maturation in the circulation over roughly one to two days. The
other outcomes would point to different physiologic functions rather than intact reticulocyte activity.
CHAMBERLAIN UNIVERSITY
Question 1. Which two-part description of reticulocyte is physiologically accurate?
A. It serves as an immature erythrocyte whose abundance reflects recent bone-marrow red-cell output; this is
enabled because its shape increases surface-area-to-volume ratio and flexibility while hemoglobin binds respiratory
gases.
B. It serves as an immature erythrocyte whose abundance reflects recent bone-marrow red-cell output; this is
enabled because newly released erythroid cells complete maturation in the circulation over roughly one to two days.
C. It serves as an immature erythrocyte whose abundance reflects recent bone-marrow red-cell output; this is
enabled because renal oxygen sensing increases erythropoietin secretion, which promotes survival and
differentiation of erythroid precursors.
D. It serves as an immature erythrocyte whose abundance reflects recent bone-marrow red-cell output; this is
enabled because oxygen reversibly binds to iron in heme groups, allowing loading in lungs and unloading in tissues.
Correct Answer: B. It serves as an immature erythrocyte whose abundance reflects recent bone-marrow red-cell
output; this is enabled because newly released erythroid cells complete maturation in the circulation over roughly
one to two days.
Explanation: The correct pairing links reticulocyte to this role: serves as an immature erythrocyte whose abundance
reflects recent bone-marrow red-cell output, and to this mechanism: newly released erythroid cells complete maturation
in the circulation over roughly one to two days. A correct function paired with the wrong mechanism is still an incorrect
description. The other options deliberately mix the role of reticulocyte with mechanisms that belong to different
components.
Question 2. Which change is the most direct prediction when Frank-Starling mechanism is markedly
abnormal?
A. whole-body blood flow would decrease if output fell substantially without compensation
B. cardiac output would fall if heart rate did not increase to compensate
C. heart rate and contractile reserve during increased demand would be reduced
D. the heart would be less able to adjust stroke volume to short-term changes in venous return
Correct Answer: D. the heart would be less able to adjust stroke volume to short-term changes in venous return
Explanation: The most direct consequence is that the heart would be less able to adjust stroke volume to short-term
changes in venous return. That prediction follows because Frank-Starling mechanism normally has this role: matches
ventricular output to venous return by increasing force of contraction as myocardial fibers are stretched within
physiologic limits. The distractors reflect dysfunction of other structures or processes rather than the most direct
consequence here.
Question 3. Which option accurately links a hallmark of basophil with the expected result of major
impairment?
A. Feature: it is a granulocyte with a bilobed nucleus and prominent red-orange granules / Dysfunction: some
immediate inflammatory signaling and hypersensitivity responses would be blunted.
B. Feature: it is the most abundant circulating leukocyte and has a multilobed nucleus with pale granules /
Dysfunction: some immediate inflammatory signaling and hypersensitivity responses would be blunted.
C. Feature: it is typically the largest leukocyte in a blood smear and has a kidney-shaped nucleus / Dysfunction:
some immediate inflammatory signaling and hypersensitivity responses would be blunted.
D. Feature: it is a rare circulating granulocyte whose dark granules may obscure its bilobed nucleus / Dysfunction:
some immediate inflammatory signaling and hypersensitivity responses would be blunted.
Correct Answer: D. Feature: it is a rare circulating granulocyte whose dark granules may obscure its bilobed
nucleus / Dysfunction: some immediate inflammatory signaling and hypersensitivity responses would be blunted.
Explanation: For basophil, the identifying feature is that it is a rare circulating granulocyte whose dark granules may
obscure its bilobed nucleus, and severe dysfunction would mean that some immediate inflammatory signaling and
,hypersensitivity responses would be blunted. 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 4. A learner notes the following feature: it can be calculated as end-diastolic volume minus
end-systolic volume. Which structure or process is being described?
A. Frank-Starling mechanism
B. sympathetic cardiac stimulation
C. stroke volume
D. cardiac output
Correct Answer: C. stroke volume
Explanation: The description identifies stroke volume because it can be calculated as end-diastolic volume minus
end-systolic volume. Its key role is that it represents the volume ejected by one ventricle during a single heartbeat. The
alternative options have different defining features and would not best fit the description.
Question 5. Which two-part description of eosinophil is physiologically accurate?
A. It helps defend against multicellular parasites and participates in allergic inflammation; this is enabled because
granule proteins can damage parasites while mediators modify inflammatory and allergic responses.
B. It helps defend against multicellular parasites and participates in allergic inflammation; this is enabled because
after leaving the bloodstream it differentiates into long-lived tissue phagocytes that ingest debris and pathogens.
C. It helps defend against multicellular parasites and participates in allergic inflammation; this is enabled because
degranulation releases vasoactive and inflammatory mediators, including histamine.
D. It helps defend against multicellular parasites and participates in allergic inflammation; this is enabled because
different lymphocyte subsets recognize antigens, produce antibodies, coordinate immunity, or kill abnormal cells.
Correct Answer: A. It helps defend against multicellular parasites and participates in allergic inflammation; this
is enabled because granule proteins can damage parasites while mediators modify inflammatory and allergic
responses.
Explanation: The correct pairing links eosinophil to this role: helps defend against multicellular parasites and
participates in allergic inflammation, and to this mechanism: granule proteins can damage parasites while mediators
modify inflammatory and allergic responses. A correct function paired with the wrong mechanism is still an incorrect
description. The other options deliberately mix the role of eosinophil with mechanisms that belong to different
components.
Question 6. Which normal function best matches atrioventricular node?
A. rapidly distributes electrical excitation through the ventricles to coordinate ventricular contraction
B. represents atrial depolarization
C. delays conduction from atria to ventricles so ventricular filling can proceed before ventricular depolarization
D. deliver oxygenated blood to the myocardium so cardiac muscle can sustain continuous work
Correct Answer: C. delays conduction from atria to ventricles so ventricular filling can proceed before
ventricular depolarization
Explanation: The correct choice describes this function: delays conduction from atria to ventricles so ventricular filling
can proceed before ventricular depolarization. This is the primary role associated with atrioventricular node, and it is
supported by the mechanism that slow conduction through nodal tissue creates the normal delay before impulses enter
the AV bundle. The other choices describe functions performed by different components within the same course domain.
,Question 7. A patient forms an initial platelet plug, but the plug repeatedly breaks down because fibrin
strands do not develop. Which explanation best accounts for this finding?
A. vascular spasm is the rapid vasoconstrictor phase of hemostasis
B. failure of platelet adhesion disrupts primary hemostasis and plug formation
C. the defect lies in coagulation, which normally stabilizes the plug with fibrin
D. the bleeding pattern reflects impaired platelet plug formation
Correct Answer: C. the defect lies in coagulation, which normally stabilizes the plug with fibrin
Explanation: The best interpretation is that the defect lies in coagulation, which normally stabilizes the plug with fibrin.
This scenario centers on coagulation, whose normal physiologic role is described as follows: stabilizes hemostasis by
generating fibrin strands that reinforce the platelet plug. That relationship is more directly supported by the stated
findings than the alternative explanations.
Question 8. Which effect would most directly accompany severe disruption of coronary arteries?
A. ventricular depolarization would become slower or less coordinated
B. myocardial ischemia and reduced contractile function could develop when flow is severely limited
C. a slower subsidiary pacemaker could take over if this node failed completely
D. atrial impulses would reach the ventricles with abnormal timing or might fail to conduct normally
Correct Answer: B. myocardial ischemia and reduced contractile function could develop when flow is severely
limited
Explanation: The most direct consequence is that myocardial ischemia and reduced contractile function could develop
when flow is severely limited. That prediction follows because coronary arteries normally has this role: deliver
oxygenated blood to the myocardium so cardiac muscle can sustain continuous work. The distractors reflect dysfunction
of other structures or processes rather than the most direct consequence here.
Question 9. Which feature is most characteristic of platelet?
A. it is the earliest local response in hemostasis and occurs before a stable fibrin clot is formed
B. it is a small anucleate cell fragment shed from megakaryocytes
C. its final common pathway produces thrombin, which converts fibrinogen to fibrin
D. it depends strongly on platelet binding to exposed subendothelial structures and to one another
Correct Answer: B. it is a small anucleate cell fragment shed from megakaryocytes
Explanation: The identifying feature is that it is a small anucleate cell fragment shed from megakaryocytes. That
characteristic is consistent with platelet and its normal role: forms the initial platelet plug and provides a phospholipid
surface that supports coagulation reactions. The other findings are characteristic of different items and do not identify
platelet as precisely.
Question 10. Which item matches this identifying characteristic: it is the small deflection that normally
precedes the QRS complex?
A. P wave of the ECG
B. atrioventricular node
C. His-Purkinje conduction system
D. QRS complex of the ECG
Correct Answer: A. P wave of the ECG
Explanation: The description identifies P wave of the ECG because it is the small deflection that normally precedes the
QRS complex. Its key role is that it represents atrial depolarization. The alternative options have different defining
features and would not best fit the description.
, Question 11. Which result best demonstrates that hemoglobin is functioning normally?
A. The system demonstrates that it binds most oxygen carried in blood and participates in buffering and carbon
dioxide transport.
B. The system demonstrates that it transports oxygen and contributes to carbon dioxide transport through
hemoglobin and intracellular enzymes.
C. The system demonstrates that it serves as an immature erythrocyte whose abundance reflects recent
bone-marrow red-cell output.
D. The system demonstrates that it stimulates red bone marrow to increase erythrocyte production when tissue
oxygen availability is low.
Correct Answer: A. The system demonstrates that it binds most oxygen carried in blood and participates in
buffering and carbon dioxide transport.
Explanation: The strongest evidence is the outcome linked to the normal role of hemoglobin: binds most oxygen carried
in blood and participates in buffering and carbon dioxide transport. This expected result depends on the mechanism that
oxygen reversibly binds to iron in heme groups, allowing loading in lungs and unloading in tissues. The other outcomes
would point to different physiologic functions rather than intact hemoglobin activity.
Question 12. A learner notes the following feature: it equals heart rate multiplied by stroke volume.
Which structure or process is being described?
A. Frank-Starling mechanism
B. sympathetic cardiac stimulation
C. stroke volume
D. cardiac output
Correct Answer: D. cardiac output
Explanation: The description identifies cardiac output because it equals heart rate multiplied by stroke volume. Its key
role is that it expresses the volume of blood pumped by one ventricle per minute. The alternative options have different
defining features and would not best fit the description.
Question 13. Which observation would provide the strongest evidence of normal reticulocyte function?
A. The system demonstrates that it transports oxygen and contributes to carbon dioxide transport through
hemoglobin and intracellular enzymes.
B. The system demonstrates that it binds most oxygen carried in blood and participates in buffering and carbon
dioxide transport.
C. The system demonstrates that it serves as an immature erythrocyte whose abundance reflects recent
bone-marrow red-cell output.
D. The system demonstrates that it stimulates red bone marrow to increase erythrocyte production when tissue
oxygen availability is low.
Correct Answer: C. The system demonstrates that it serves as an immature erythrocyte whose abundance
reflects recent bone-marrow red-cell output.
Explanation: The strongest evidence is the outcome linked to the normal role of reticulocyte: serves as an immature
erythrocyte whose abundance reflects recent bone-marrow red-cell output. This expected result depends on the
mechanism that newly released erythroid cells complete maturation in the circulation over roughly one to two days. The
other outcomes would point to different physiologic functions rather than intact reticulocyte activity.
