Human Biology
Proctored Final Exam Review
(With Solutions)
2026
1
,Multiple Choice (10 questions)
A patient with chronic kidney disease shows elevated serum
phosphate and decreased calcium levels. Which hormone is
primarily responsible for these abnormalities?
A) Calcitonin
B) Parathyroid hormone (PTH)
C) Aldosterone
D) Antidiuretic hormone (ADH)
Answer: B) Parathyroid hormone (PTH)
Rationale: PTH increases serum calcium by stimulating bone
resorption and activating vitamin D; in kidney disease, phosphate
excretion decreases, leading to hyperphosphatemia that lowers
serum calcium, stimulating PTH release.
Which of the following best describes the phase of the cardiac cycle
where the ventricles contract and the semilunar valves are open?
A) Isovolumetric relaxation
B) Ventricular filling
C) Ventricular systole (ejection phase)
D) Atrial systole
Answer: C) Ventricular systole (ejection phase)
Rationale: Ventricular systole ejects blood into the arteries when
semilunar valves open.
In type 1 diabetes mellitus, destruction of pancreatic beta cells
results in a deficiency of which hormone?
A) Glucagon
B) Insulin
C) Somatostatin
D) Amylin
Answer: B) Insulin
Rationale: Beta cells produce insulin, essential for glucose uptake.
Which type of muscle fiber is most fatigue-resistant and used
2
, predominantly during prolonged aerobic activities?
A) Type I fibers
B) Type IIa fibers
C) Type IIb fibers
D) Cardiac fibers
Answer: A) Type I fibers
Rationale: Type I fibers have high mitochondria density and rely on
oxidative metabolism.
Which part of the nephron is primarily responsible for the
reabsorption of glucose?
A) Glomerulus
B) Proximal convoluted tubule
C) Loop of Henle
D) Distal convoluted tubule
Answer: B) Proximal convoluted tubule
Rationale: The proximal tubule reabsorbs almost all glucose via
sodium-glucose cotransporters.
Which cell type plays the most critical role in antigen-presenting and
activating adaptive immunity?
A) Neutrophils
B) B cells
C) Dendritic cells
D) Eosinophils
Answer: C) Dendritic cells
Rationale: Dendritic cells present antigens to T cells, initiating the
immune response.
In respiratory physiology, the majority of carbon dioxide in blood is
transported as:
A) Dissolved CO2 in plasma
B) Carbaminohemoglobin
C) Bicarbonate (HCO3-) ions
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