BIOLOGY 251 Lecture Exam 4 (Final) | Full Questions, Correct Answers, and Rationales |
2026 Update | 100% Correct – WSU.
Part I: New Material
1. During which renal process are molecules selectively removed from the
tubular lumen, transported into tubular cells, and then moved into the
peritubular capillaries?
A. Filtration
B. Secretion
C. Excretion
D. Reabsorption
E. Absorption
Correct answer: D. Reabsorption
Rationale: Tubular reabsorption moves filtered substances from the nephron lumen back into the
blood. Secretion moves substances in the opposite direction—from the blood into the tubule.
2. Collecting-duct epithelial cells contain receptors for which hormone that
stimulates water reabsorption?
A. Antidiuretic hormone
B. Renin
C. Aldosterone
D. Epinephrine
E. Erythropoietin
Correct answer: A. Antidiuretic hormone
Rationale: ADH binds V₂ receptors on collecting-duct principal cells and promotes insertion of
aquaporin-2 water channels into the apical membrane.
3. Glucose is reabsorbed by proximal convoluted-tubule cells using which apical
transporters?
A. Ion channels
B. Passive carrier proteins
C. Glucose ATPases
, D. Potassium-linked secondary active transporters
E. Sodium-linked secondary active transporters
Correct answer: E
Rationale: Sodium-glucose cotransporters use the sodium gradient established by the sodium-
potassium pump to move glucose from tubular fluid into epithelial cells.
4. Which is not a function of the kidneys?
A. Regulation of plasma ion concentration
B. Regulation of plasma osmolarity
C. Regulation of plasma temperature
D. Regulation of plasma volume
E. Regulation of plasma pH
Correct answer: C. Regulation of plasma temperature
Rationale: The kidneys regulate fluid volume, osmolarity, electrolytes, acid-base balance, waste
removal, and several hormones. Thermoregulation is not a principal renal function.
5. In tubuloglomerular feedback, an increased GFR increases tubular fluid
delivery and stimulates paracrine signals that:
A. Dilate afferent arterioles and further increase GFR
B. Constrict afferent arterioles and decrease GFR
C. Constrict afferent arterioles and increase GFR
D. Reduce glomerular-capillary osmotic pressure and increase GFR
E. Have no effect on GFR
Correct answer: B
Rationale: Increased sodium chloride delivery to the macula densa leads to afferent arteriolar
constriction, lowering glomerular pressure and returning GFR toward normal.
6. A hemorrhage-induced decrease in MAP decreases GFR by increasing which
activity and constricting the afferent arterioles?
A. Parasympathetic and somatic activity
B. Parasympathetic activity only
2026 Update | 100% Correct – WSU.
Part I: New Material
1. During which renal process are molecules selectively removed from the
tubular lumen, transported into tubular cells, and then moved into the
peritubular capillaries?
A. Filtration
B. Secretion
C. Excretion
D. Reabsorption
E. Absorption
Correct answer: D. Reabsorption
Rationale: Tubular reabsorption moves filtered substances from the nephron lumen back into the
blood. Secretion moves substances in the opposite direction—from the blood into the tubule.
2. Collecting-duct epithelial cells contain receptors for which hormone that
stimulates water reabsorption?
A. Antidiuretic hormone
B. Renin
C. Aldosterone
D. Epinephrine
E. Erythropoietin
Correct answer: A. Antidiuretic hormone
Rationale: ADH binds V₂ receptors on collecting-duct principal cells and promotes insertion of
aquaporin-2 water channels into the apical membrane.
3. Glucose is reabsorbed by proximal convoluted-tubule cells using which apical
transporters?
A. Ion channels
B. Passive carrier proteins
C. Glucose ATPases
, D. Potassium-linked secondary active transporters
E. Sodium-linked secondary active transporters
Correct answer: E
Rationale: Sodium-glucose cotransporters use the sodium gradient established by the sodium-
potassium pump to move glucose from tubular fluid into epithelial cells.
4. Which is not a function of the kidneys?
A. Regulation of plasma ion concentration
B. Regulation of plasma osmolarity
C. Regulation of plasma temperature
D. Regulation of plasma volume
E. Regulation of plasma pH
Correct answer: C. Regulation of plasma temperature
Rationale: The kidneys regulate fluid volume, osmolarity, electrolytes, acid-base balance, waste
removal, and several hormones. Thermoregulation is not a principal renal function.
5. In tubuloglomerular feedback, an increased GFR increases tubular fluid
delivery and stimulates paracrine signals that:
A. Dilate afferent arterioles and further increase GFR
B. Constrict afferent arterioles and decrease GFR
C. Constrict afferent arterioles and increase GFR
D. Reduce glomerular-capillary osmotic pressure and increase GFR
E. Have no effect on GFR
Correct answer: B
Rationale: Increased sodium chloride delivery to the macula densa leads to afferent arteriolar
constriction, lowering glomerular pressure and returning GFR toward normal.
6. A hemorrhage-induced decrease in MAP decreases GFR by increasing which
activity and constricting the afferent arterioles?
A. Parasympathetic and somatic activity
B. Parasympathetic activity only
