BIOS 256 Exam Prep Questions and Answers with Rationales |
CHAMBERLAIN UNIVERSITY
Question 1. When reviewing normal anatomy and physiology, which feature belongs to Leydig cells?
A. it includes mitosis, meiosis, and spermiogenesis within seminiferous tubules
B. they extend from the basement membrane toward the lumen within seminiferous tubules
C. they are highly coiled tubules lined by developing germ cells and supporting Sertoli cells
D. they are located in the interstitial tissue between seminiferous tubules
Correct Answer: D. they are located in the interstitial tissue between seminiferous tubules
Explanation: The identifying feature is that they are located in the interstitial tissue between seminiferous tubules. That
characteristic is consistent with Leydig cells and its normal role: secrete testosterone in response to luteinizing hormone.
The other findings are characteristic of different items and do not identify Leydig cells as precisely.
Question 2. A patient or laboratory scenario shows the following: A patient taking a potassium-sparing
drug develops weakness and ECG changes with elevated serum potassium. Which interpretation is most
accurate?
A. the higher extracellular osmolarity draws water out of cells
B. water moves between ICF and ECF according to osmotic gradients
C. water follows retained sodium, expanding the extracellular compartment
D. altered potassium balance can disturb membrane potentials in excitable tissues
Correct Answer: D. altered potassium balance can disturb membrane potentials in excitable tissues
Explanation: The best interpretation is that altered potassium balance can disturb membrane potentials in excitable
tissues. This scenario centers on potassium balance, whose normal physiologic role is described as follows: maintains
the major intracellular cation needed for normal membrane excitability. That relationship is more directly supported by
the stated findings than the alternative explanations.
Question 3. Which normal outcome is most directly associated with intact juxtaglomerular apparatus
physiology?
A. The system demonstrates that it filters water and small solutes from glomerular blood into capsular space.
B. The system demonstrates that it form the visceral layer of the glomerular capsule and contribute filtration slits to
the renal filtration barrier.
C. The system demonstrates that it links distal tubular sodium delivery and arteriolar pressure to renin release and
filtration control.
D. The system demonstrates that it permits water and small solutes to enter filtrate while restricting blood cells and
most large proteins.
Correct Answer: C. The system demonstrates that it links distal tubular sodium delivery and arteriolar pressure
to renin release and filtration control.
Explanation: The strongest evidence is the outcome linked to the normal role of juxtaglomerular apparatus: links distal
tubular sodium delivery and arteriolar pressure to renin release and filtration control. This expected result depends on the
mechanism that macula densa signaling and granular-cell renin release help regulate GFR and systemic blood pressure.
The other outcomes would point to different physiologic functions rather than intact juxtaglomerular apparatus activity.
,Question 4. Severe dysfunction involving antidiuretic hormone action would be expected to cause which
outcome first?
A. urine becomes dilute and water loss rises when ADH is absent or ineffective
B. electrolyte homeostasis would be less precise if distal nephron transport could not adjust
C. potassium excretion would fall and sodium retention would decrease if aldosterone action were blocked
D. the corticomedullary osmotic gradient and ability to produce concentrated urine would be reduced if this
segment failed
Correct Answer: A. urine becomes dilute and water loss rises when ADH is absent or ineffective
Explanation: The most direct consequence is that urine becomes dilute and water loss rises when ADH is absent or
ineffective. That prediction follows because antidiuretic hormone action normally has this role: reduces water loss by
increasing collecting-duct water permeability. The distractors reflect dysfunction of other structures or processes rather
than the most direct consequence here.
Question 5. When reviewing normal anatomy and physiology, which feature belongs to vagina?
A. cervical mucus becomes thinner near ovulation and thicker under progesterone influence
B. it is released from the anterior pituitary, especially when suckling reduces hypothalamic dopamine influence
C. it is a distensible fibromuscular tube lined by stratified squamous epithelium
D. it is released from the posterior pituitary in response to suckling-related neural input
Correct Answer: C. it is a distensible fibromuscular tube lined by stratified squamous epithelium
Explanation: The identifying feature is that it is a distensible fibromuscular tube lined by stratified squamous epithelium.
That characteristic is consistent with vagina and its normal role: serves as the copulatory canal, passage for menstrual
flow, and part of the birth canal. The other findings are characteristic of different items and do not identify vagina as
precisely.
Question 6. Which process provides the best mechanistic explanation for arterial blood pH?
A. carbon dioxide hydration and dissociation allow added acid or base to be buffered while lungs and kidneys adjust
system components
B. buffers, lungs, and kidneys coordinate control of hydrogen ion concentration
C. filtered phosphate can bind secreted hydrogen ions in the nephron and permit net acid excretion
D. amino acid side chains can accept or release hydrogen ions as pH changes
Correct Answer: B. buffers, lungs, and kidneys coordinate control of hydrogen ion concentration
Explanation: The correct mechanism is that buffers, lungs, and kidneys coordinate control of hydrogen ion
concentration. It explains the normal function of arterial blood pH: is normally maintained in a narrow range of about
7.35 to 7.45. The other mechanisms belong to different structures or processes in the same broad system.
Question 7. A student is distinguishing closely related structures and processes. Which finding best
identifies hypothalamic-pituitary-gonadal axis in males?
A. erection is primarily parasympathetic and vascular, while emission and much of ejaculation depend on
sympathetic and somatic activity
B. GnRH stimulates pituitary LH and FSH, while testosterone and inhibin provide negative feedback
C. they are small paired glands whose ducts open into the spongy urethra
D. it is secreted mainly by Sertoli cells
Correct Answer: B. GnRH stimulates pituitary LH and FSH, while testosterone and inhibin provide negative
feedback
Explanation: The identifying feature is that GnRH stimulates pituitary LH and FSH, while testosterone and inhibin
provide negative feedback. That characteristic is consistent with hypothalamic-pituitary-gonadal axis in males and its
normal role: coordinates testosterone production and spermatogenesis. The other findings are characteristic of different
items and do not identify hypothalamic-pituitary-gonadal axis in males as precisely.
,Question 8. Which result best demonstrates that podocytes is functioning normally?
A. The system demonstrates that it permits water and small solutes to enter filtrate while restricting blood cells and
most large proteins.
B. The system demonstrates that it filters water and small solutes from glomerular blood into capsular space.
C. The system demonstrates that it links distal tubular sodium delivery and arteriolar pressure to renin release and
filtration control.
D. The system demonstrates that it form the visceral layer of the glomerular capsule and contribute filtration slits to
the renal filtration barrier.
Correct Answer: D. The system demonstrates that it form the visceral layer of the glomerular capsule and
contribute filtration slits to the renal filtration barrier.
Explanation: The strongest evidence is the outcome linked to the normal role of podocytes: form the visceral layer of the
glomerular capsule and contribute filtration slits to the renal filtration barrier. This expected result depends on the
mechanism that slit diaphragms between processes add selective resistance to macromolecule passage. The other
outcomes would point to different physiologic functions rather than intact podocytes activity.
Question 9. Which effect would most directly accompany severe disruption of renal clearance?
A. volume and pressure support during hypovolemia would be weakened if the cascade were blocked
B. clearance measurements become abnormal when filtration or tubular handling changes
C. maximal urine concentration would fall if the medullary gradient collapsed
D. volume reduction would be less efficient during atrial stretch if ANP signaling were absent
Correct Answer: B. clearance measurements become abnormal when filtration or tubular handling changes
Explanation: The most direct consequence is that clearance measurements become abnormal when filtration or tubular
handling changes. That prediction follows because renal clearance normally has this role: describes the virtual volume of
plasma cleared of a substance by the kidneys per unit time. The distractors reflect dysfunction of other structures or
processes rather than the most direct consequence here.
Question 10. Which process provides the best mechanistic explanation for autosomal dominant
inheritance?
A. males who inherit the altered allele on their single X lack a second X-linked copy that might mask it
B. during meiosis a heterozygous parent places the altered allele into about half of gametes
C. homologous chromosomes separate in meiosis I and sister chromatids separate in meiosis II
D. many alleles contribute small effects that interact with nutrition, exposures, or other environmental factors
Correct Answer: B. during meiosis a heterozygous parent places the altered allele into about half of gametes
Explanation: The correct mechanism is that during meiosis a heterozygous parent places the altered allele into about half
of gametes. It explains the normal function of autosomal dominant inheritance: can produce a trait when one altered
allele on an autosome is sufficient for expression. The other mechanisms belong to different structures or processes in
the same broad system.
, Question 11. Which pairing correctly links amino acid absorption with its function and mechanism?
A. It transfers products of protein digestion into the blood of intestinal villi; this is enabled because
sodium-dependent transporters and peptide cotransporters move nitrogen-containing nutrients into epithelial cells.
B. It transfers products of protein digestion into the blood of intestinal villi; this is enabled because slow transit
permits salt and water absorption while mucus lubricates increasingly solid contents.
C. It transfers products of protein digestion into the blood of intestinal villi; this is enabled because parasympathetic
signaling increases rectal and sigmoid contractions while voluntary control of the external sphincter determines
timing.
D. It transfers products of protein digestion into the blood of intestinal villi; this is enabled because bile salts
facilitate delivery to the membrane, and chylomicrons enter lacteals because they are too large for typical blood
capillaries.
Correct Answer: A. It transfers products of protein digestion into the blood of intestinal villi; this is enabled
because sodium-dependent transporters and peptide cotransporters move nitrogen-containing nutrients into
epithelial cells.
Explanation: The correct pairing links amino acid absorption to this role: transfers products of protein digestion into the
blood of intestinal villi, and to this mechanism: sodium-dependent transporters and peptide cotransporters move
nitrogen-containing nutrients into epithelial cells. A correct function paired with the wrong mechanism is still an
incorrect description. The other options deliberately mix the role of amino acid absorption with mechanisms that belong
to different components.
Question 12. How is the normal role of human chorionic gonadotropin carried out most directly?
A. rapid differentiation and morphogenesis create critical windows in which disruptive exposures can alter structure
B. hCG acts similarly to LH on the corpus luteum, sustaining progesterone secretion
C. placental oxygenation and pressure relationships route blood through these shunts before birth
D. diffusion and transporter-mediated exchange occur across a thin placental barrier, and endocrine cells secrete
pregnancy-supporting hormones
Correct Answer: B. hCG acts similarly to LH on the corpus luteum, sustaining progesterone secretion
Explanation: The correct mechanism is that hCG acts similarly to LH on the corpus luteum, sustaining progesterone
secretion. It explains the normal function of human chorionic gonadotropin: maintains the corpus luteum in early
pregnancy until placental steroid production is established. The other mechanisms belong to different structures or
processes in the same broad system.
Question 13. When reviewing normal anatomy and physiology, which feature belongs to seminal
vesicles?
A. it is a thick-walled muscular tube within the spermatic cord
B. it surrounds the proximal urethra inferior to the bladder
C. it is a long coiled duct along the posterior surface of the testis
D. paired glands empty into the ejaculatory ducts
Correct Answer: D. paired glands empty into the ejaculatory ducts
Explanation: The identifying feature is that paired glands empty into the ejaculatory ducts. That characteristic is
consistent with seminal vesicles and its normal role: contribute most of the fluid volume of semen and provide nutrients
and signaling molecules. The other findings are characteristic of different items and do not identify seminal vesicles as
precisely.
CHAMBERLAIN UNIVERSITY
Question 1. When reviewing normal anatomy and physiology, which feature belongs to Leydig cells?
A. it includes mitosis, meiosis, and spermiogenesis within seminiferous tubules
B. they extend from the basement membrane toward the lumen within seminiferous tubules
C. they are highly coiled tubules lined by developing germ cells and supporting Sertoli cells
D. they are located in the interstitial tissue between seminiferous tubules
Correct Answer: D. they are located in the interstitial tissue between seminiferous tubules
Explanation: The identifying feature is that they are located in the interstitial tissue between seminiferous tubules. That
characteristic is consistent with Leydig cells and its normal role: secrete testosterone in response to luteinizing hormone.
The other findings are characteristic of different items and do not identify Leydig cells as precisely.
Question 2. A patient or laboratory scenario shows the following: A patient taking a potassium-sparing
drug develops weakness and ECG changes with elevated serum potassium. Which interpretation is most
accurate?
A. the higher extracellular osmolarity draws water out of cells
B. water moves between ICF and ECF according to osmotic gradients
C. water follows retained sodium, expanding the extracellular compartment
D. altered potassium balance can disturb membrane potentials in excitable tissues
Correct Answer: D. altered potassium balance can disturb membrane potentials in excitable tissues
Explanation: The best interpretation is that altered potassium balance can disturb membrane potentials in excitable
tissues. This scenario centers on potassium balance, whose normal physiologic role is described as follows: maintains
the major intracellular cation needed for normal membrane excitability. That relationship is more directly supported by
the stated findings than the alternative explanations.
Question 3. Which normal outcome is most directly associated with intact juxtaglomerular apparatus
physiology?
A. The system demonstrates that it filters water and small solutes from glomerular blood into capsular space.
B. The system demonstrates that it form the visceral layer of the glomerular capsule and contribute filtration slits to
the renal filtration barrier.
C. The system demonstrates that it links distal tubular sodium delivery and arteriolar pressure to renin release and
filtration control.
D. The system demonstrates that it permits water and small solutes to enter filtrate while restricting blood cells and
most large proteins.
Correct Answer: C. The system demonstrates that it links distal tubular sodium delivery and arteriolar pressure
to renin release and filtration control.
Explanation: The strongest evidence is the outcome linked to the normal role of juxtaglomerular apparatus: links distal
tubular sodium delivery and arteriolar pressure to renin release and filtration control. This expected result depends on the
mechanism that macula densa signaling and granular-cell renin release help regulate GFR and systemic blood pressure.
The other outcomes would point to different physiologic functions rather than intact juxtaglomerular apparatus activity.
,Question 4. Severe dysfunction involving antidiuretic hormone action would be expected to cause which
outcome first?
A. urine becomes dilute and water loss rises when ADH is absent or ineffective
B. electrolyte homeostasis would be less precise if distal nephron transport could not adjust
C. potassium excretion would fall and sodium retention would decrease if aldosterone action were blocked
D. the corticomedullary osmotic gradient and ability to produce concentrated urine would be reduced if this
segment failed
Correct Answer: A. urine becomes dilute and water loss rises when ADH is absent or ineffective
Explanation: The most direct consequence is that urine becomes dilute and water loss rises when ADH is absent or
ineffective. That prediction follows because antidiuretic hormone action normally has this role: reduces water loss by
increasing collecting-duct water permeability. The distractors reflect dysfunction of other structures or processes rather
than the most direct consequence here.
Question 5. When reviewing normal anatomy and physiology, which feature belongs to vagina?
A. cervical mucus becomes thinner near ovulation and thicker under progesterone influence
B. it is released from the anterior pituitary, especially when suckling reduces hypothalamic dopamine influence
C. it is a distensible fibromuscular tube lined by stratified squamous epithelium
D. it is released from the posterior pituitary in response to suckling-related neural input
Correct Answer: C. it is a distensible fibromuscular tube lined by stratified squamous epithelium
Explanation: The identifying feature is that it is a distensible fibromuscular tube lined by stratified squamous epithelium.
That characteristic is consistent with vagina and its normal role: serves as the copulatory canal, passage for menstrual
flow, and part of the birth canal. The other findings are characteristic of different items and do not identify vagina as
precisely.
Question 6. Which process provides the best mechanistic explanation for arterial blood pH?
A. carbon dioxide hydration and dissociation allow added acid or base to be buffered while lungs and kidneys adjust
system components
B. buffers, lungs, and kidneys coordinate control of hydrogen ion concentration
C. filtered phosphate can bind secreted hydrogen ions in the nephron and permit net acid excretion
D. amino acid side chains can accept or release hydrogen ions as pH changes
Correct Answer: B. buffers, lungs, and kidneys coordinate control of hydrogen ion concentration
Explanation: The correct mechanism is that buffers, lungs, and kidneys coordinate control of hydrogen ion
concentration. It explains the normal function of arterial blood pH: is normally maintained in a narrow range of about
7.35 to 7.45. The other mechanisms belong to different structures or processes in the same broad system.
Question 7. A student is distinguishing closely related structures and processes. Which finding best
identifies hypothalamic-pituitary-gonadal axis in males?
A. erection is primarily parasympathetic and vascular, while emission and much of ejaculation depend on
sympathetic and somatic activity
B. GnRH stimulates pituitary LH and FSH, while testosterone and inhibin provide negative feedback
C. they are small paired glands whose ducts open into the spongy urethra
D. it is secreted mainly by Sertoli cells
Correct Answer: B. GnRH stimulates pituitary LH and FSH, while testosterone and inhibin provide negative
feedback
Explanation: The identifying feature is that GnRH stimulates pituitary LH and FSH, while testosterone and inhibin
provide negative feedback. That characteristic is consistent with hypothalamic-pituitary-gonadal axis in males and its
normal role: coordinates testosterone production and spermatogenesis. The other findings are characteristic of different
items and do not identify hypothalamic-pituitary-gonadal axis in males as precisely.
,Question 8. Which result best demonstrates that podocytes is functioning normally?
A. The system demonstrates that it permits water and small solutes to enter filtrate while restricting blood cells and
most large proteins.
B. The system demonstrates that it filters water and small solutes from glomerular blood into capsular space.
C. The system demonstrates that it links distal tubular sodium delivery and arteriolar pressure to renin release and
filtration control.
D. The system demonstrates that it form the visceral layer of the glomerular capsule and contribute filtration slits to
the renal filtration barrier.
Correct Answer: D. The system demonstrates that it form the visceral layer of the glomerular capsule and
contribute filtration slits to the renal filtration barrier.
Explanation: The strongest evidence is the outcome linked to the normal role of podocytes: form the visceral layer of the
glomerular capsule and contribute filtration slits to the renal filtration barrier. This expected result depends on the
mechanism that slit diaphragms between processes add selective resistance to macromolecule passage. The other
outcomes would point to different physiologic functions rather than intact podocytes activity.
Question 9. Which effect would most directly accompany severe disruption of renal clearance?
A. volume and pressure support during hypovolemia would be weakened if the cascade were blocked
B. clearance measurements become abnormal when filtration or tubular handling changes
C. maximal urine concentration would fall if the medullary gradient collapsed
D. volume reduction would be less efficient during atrial stretch if ANP signaling were absent
Correct Answer: B. clearance measurements become abnormal when filtration or tubular handling changes
Explanation: The most direct consequence is that clearance measurements become abnormal when filtration or tubular
handling changes. That prediction follows because renal clearance normally has this role: describes the virtual volume of
plasma cleared of a substance by the kidneys per unit time. The distractors reflect dysfunction of other structures or
processes rather than the most direct consequence here.
Question 10. Which process provides the best mechanistic explanation for autosomal dominant
inheritance?
A. males who inherit the altered allele on their single X lack a second X-linked copy that might mask it
B. during meiosis a heterozygous parent places the altered allele into about half of gametes
C. homologous chromosomes separate in meiosis I and sister chromatids separate in meiosis II
D. many alleles contribute small effects that interact with nutrition, exposures, or other environmental factors
Correct Answer: B. during meiosis a heterozygous parent places the altered allele into about half of gametes
Explanation: The correct mechanism is that during meiosis a heterozygous parent places the altered allele into about half
of gametes. It explains the normal function of autosomal dominant inheritance: can produce a trait when one altered
allele on an autosome is sufficient for expression. The other mechanisms belong to different structures or processes in
the same broad system.
, Question 11. Which pairing correctly links amino acid absorption with its function and mechanism?
A. It transfers products of protein digestion into the blood of intestinal villi; this is enabled because
sodium-dependent transporters and peptide cotransporters move nitrogen-containing nutrients into epithelial cells.
B. It transfers products of protein digestion into the blood of intestinal villi; this is enabled because slow transit
permits salt and water absorption while mucus lubricates increasingly solid contents.
C. It transfers products of protein digestion into the blood of intestinal villi; this is enabled because parasympathetic
signaling increases rectal and sigmoid contractions while voluntary control of the external sphincter determines
timing.
D. It transfers products of protein digestion into the blood of intestinal villi; this is enabled because bile salts
facilitate delivery to the membrane, and chylomicrons enter lacteals because they are too large for typical blood
capillaries.
Correct Answer: A. It transfers products of protein digestion into the blood of intestinal villi; this is enabled
because sodium-dependent transporters and peptide cotransporters move nitrogen-containing nutrients into
epithelial cells.
Explanation: The correct pairing links amino acid absorption to this role: transfers products of protein digestion into the
blood of intestinal villi, and to this mechanism: sodium-dependent transporters and peptide cotransporters move
nitrogen-containing nutrients into epithelial cells. A correct function paired with the wrong mechanism is still an
incorrect description. The other options deliberately mix the role of amino acid absorption with mechanisms that belong
to different components.
Question 12. How is the normal role of human chorionic gonadotropin carried out most directly?
A. rapid differentiation and morphogenesis create critical windows in which disruptive exposures can alter structure
B. hCG acts similarly to LH on the corpus luteum, sustaining progesterone secretion
C. placental oxygenation and pressure relationships route blood through these shunts before birth
D. diffusion and transporter-mediated exchange occur across a thin placental barrier, and endocrine cells secrete
pregnancy-supporting hormones
Correct Answer: B. hCG acts similarly to LH on the corpus luteum, sustaining progesterone secretion
Explanation: The correct mechanism is that hCG acts similarly to LH on the corpus luteum, sustaining progesterone
secretion. It explains the normal function of human chorionic gonadotropin: maintains the corpus luteum in early
pregnancy until placental steroid production is established. The other mechanisms belong to different structures or
processes in the same broad system.
Question 13. When reviewing normal anatomy and physiology, which feature belongs to seminal
vesicles?
A. it is a thick-walled muscular tube within the spermatic cord
B. it surrounds the proximal urethra inferior to the bladder
C. it is a long coiled duct along the posterior surface of the testis
D. paired glands empty into the ejaculatory ducts
Correct Answer: D. paired glands empty into the ejaculatory ducts
Explanation: The identifying feature is that paired glands empty into the ejaculatory ducts. That characteristic is
consistent with seminal vesicles and its normal role: contribute most of the fluid volume of semen and provide nutrients
and signaling molecules. The other findings are characteristic of different items and do not identify seminal vesicles as
precisely.
