USABO Open Exam 2025/2026 Exam
Questions and Answers | A+ Score
Assured
Assume a person is placed on cortisol medication, a glucocorticoid. How
would you expect the rates of ACTH and CRF hormone production to
change in the person?
A. ACTH production would increase, CRF production would increase
B. ACTH production would increase, CRF production would decrease
C. ACTH production would decrease, CRF production would decrease
D. ACTH production would decrease, CRF production would increase
E. ACTH and CRF production would not change - 🧠 ANSWER ✔✔D. ACTH
production would decrease, CRF production would increase
The adrenal cortex reacts to stress and responds to endocrine signals.
Stressful stimuli cause the hypothalamus to secrete a releasing hormone
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,that stimulates the anterior pituitary to release the tropic hormone ACTH.
When ACTH reaches its target via the bloodstream, it stimulates cells of
the adrenal cortex to synthesize and secrete a family of steroids called
corticosteriods [There are two main types in humans: glucocorticoids, such
as cortisol and the mineralocorticoids, such as aldosterone]. The elevated
levels of corticosteriods in the blood suppress the secretion of ACTH. The
production of ACTH therefore decreases and CRF, corticoptropin-releasing
factor/hormone, increases.
Carbon particles were injected into the blood of mice. In which of the
following places would you most likely find the particles?
A. In the glomerular filtrate
B. In the adipose tissue of the liver
C. In monocytes of the spleen
D. In plasma cells of the bone marrow
E. In the loops of Henle - 🧠 ANSWER ✔✔C. In monocytes of the spleen
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,Monocytes constitute 5% of leukocytes, which are part of a phagocytic
defense (ingestion of invading organisms by white blood cells). New
monocytes circulate in the blood for only a few hours and then migrate into
tissues, developing into large macrophages. Organs of the lymphatic
system that trap "foreign" molecules and particles are the spleen, lymph
nodes, adenoid, tonsil, appendix and Peyer's patch, which is located in the
small intestine.
Kidneys provide osmoregulation for the body. Consumption of which
nutrient creates the greatest need for osmoregulation?
A. Cellulose
B. Fat
C. Oil
D. Protein
E. Starch - 🧠 ANSWER ✔✔D. Protein
Osmoregulation is the control of water balance in organisms living in
hypertonic, hypotonic, or terrestrial environments. Osmoregulation also
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
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, holds the concentration of solutes in the blood (and indirectly, the
concentration in tissues) at appropriate levels. The kidney has two distinct
regions, the outer renal cortex and the inner renal medulla, which are
packed with nephrons. Nephrons consist of the glomerulus and Bowman's
capsule. Bowman's capsule contains porous capillaries that are permeable
to water and small solutes. Proteins are large molecules, which generally
do not filter. The high concentration of proteins in the blood creates high
osmotic pressure. Osmoregulation in the kidneys maintains the body's
water balance and solute concentration in the blood
During translation in prokaryotes, the ribosome binds to:
A. the TATA box.
B. the mRNA cap.
C. the terminator sequence.
D. an enhancer sequence.
E. the Shine-Dalgarno sequence. - 🧠 ANSWER ✔✔E. the Shine-Dalgarno
sequence.
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PRIVACY STATEMENT. ALL RIGHTS RESERVED
Questions and Answers | A+ Score
Assured
Assume a person is placed on cortisol medication, a glucocorticoid. How
would you expect the rates of ACTH and CRF hormone production to
change in the person?
A. ACTH production would increase, CRF production would increase
B. ACTH production would increase, CRF production would decrease
C. ACTH production would decrease, CRF production would decrease
D. ACTH production would decrease, CRF production would increase
E. ACTH and CRF production would not change - 🧠 ANSWER ✔✔D. ACTH
production would decrease, CRF production would increase
The adrenal cortex reacts to stress and responds to endocrine signals.
Stressful stimuli cause the hypothalamus to secrete a releasing hormone
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
1
PRIVACY STATEMENT. ALL RIGHTS RESERVED
,that stimulates the anterior pituitary to release the tropic hormone ACTH.
When ACTH reaches its target via the bloodstream, it stimulates cells of
the adrenal cortex to synthesize and secrete a family of steroids called
corticosteriods [There are two main types in humans: glucocorticoids, such
as cortisol and the mineralocorticoids, such as aldosterone]. The elevated
levels of corticosteriods in the blood suppress the secretion of ACTH. The
production of ACTH therefore decreases and CRF, corticoptropin-releasing
factor/hormone, increases.
Carbon particles were injected into the blood of mice. In which of the
following places would you most likely find the particles?
A. In the glomerular filtrate
B. In the adipose tissue of the liver
C. In monocytes of the spleen
D. In plasma cells of the bone marrow
E. In the loops of Henle - 🧠 ANSWER ✔✔C. In monocytes of the spleen
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
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PRIVACY STATEMENT. ALL RIGHTS RESERVED
,Monocytes constitute 5% of leukocytes, which are part of a phagocytic
defense (ingestion of invading organisms by white blood cells). New
monocytes circulate in the blood for only a few hours and then migrate into
tissues, developing into large macrophages. Organs of the lymphatic
system that trap "foreign" molecules and particles are the spleen, lymph
nodes, adenoid, tonsil, appendix and Peyer's patch, which is located in the
small intestine.
Kidneys provide osmoregulation for the body. Consumption of which
nutrient creates the greatest need for osmoregulation?
A. Cellulose
B. Fat
C. Oil
D. Protein
E. Starch - 🧠 ANSWER ✔✔D. Protein
Osmoregulation is the control of water balance in organisms living in
hypertonic, hypotonic, or terrestrial environments. Osmoregulation also
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
3
PRIVACY STATEMENT. ALL RIGHTS RESERVED
, holds the concentration of solutes in the blood (and indirectly, the
concentration in tissues) at appropriate levels. The kidney has two distinct
regions, the outer renal cortex and the inner renal medulla, which are
packed with nephrons. Nephrons consist of the glomerulus and Bowman's
capsule. Bowman's capsule contains porous capillaries that are permeable
to water and small solutes. Proteins are large molecules, which generally
do not filter. The high concentration of proteins in the blood creates high
osmotic pressure. Osmoregulation in the kidneys maintains the body's
water balance and solute concentration in the blood
During translation in prokaryotes, the ribosome binds to:
A. the TATA box.
B. the mRNA cap.
C. the terminator sequence.
D. an enhancer sequence.
E. the Shine-Dalgarno sequence. - 🧠 ANSWER ✔✔E. the Shine-Dalgarno
sequence.
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
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PRIVACY STATEMENT. ALL RIGHTS RESERVED
