USABO CORE EXAM QUESTIONS WITH SOLUTIONS 2025
GRADED A+
✔✔RAAS - ✔✔realeased by Juxtaglomerular Apparatus in Kidney, Renin-Angiotensin-
Aldosterone-System, creates angiotensin II which stimulates adrenal glands to produce
aldosterone which increases Na+ reabsorption in the distal convoluted tube.
✔✔ANP - ✔✔Atrial Natriuretic Peptide, released in the walls of the atrial chamber in
response to high blood pressure, prevents NaCl reabsorbtion
✔✔ADH - ✔✔Anti Diuretic Hormone, temporally increases the amount of aquaporins in
the walls if the collect duct cells.
✔✔paracrine - ✔✔Hormone acts near secreting cell (ie. Histamine)
✔✔endocrine - ✔✔Hormone acts far from secreting cell, through blood stream (ie.
insulin)
✔✔Nitric Oxide (NO) - ✔✔Paracrine hormone released by epithelial cells when they
receive inadequate O2, signals vasodialation.
✔✔Thyroid Gland Hormones - ✔✔located in neck, releases:
T3 and T4 - Which regulated metabolic processes and include iodine
Calcitonin - Lowers blood calcium by stimulation Osteoblasts to deposit calcium in the
bone
✔✔Pineal Gland Hormones - ✔✔Located in Brain, secretes:
Melatonin - Controls Circadian Rhythm
✔✔Hypothalamus - ✔✔Located in midbrain, secretes:
Oxytocin - Positive feedback loop of birth
ADH - Promotes water reabsorbtion in Kidneys
✔✔Anterior Pituitary Hormones - ✔✔Located in Brain, secretes:
Follicle Stimulating Hormone and Luteinizing Hormone - Which promote the production
of gametes
Thyroid Stimulating Hormone - Stimulates Thyroid to produce T3 and T4
Andrenocorticotropic Hormone - Stimulates Adrenal Cortex
, Prolactin - Stimulates Mammary Glands
Growth Hormone - Promotes growth
✔✔Parathyroid Hormones - ✔✔Located in neck, little nodule attached to Thyroid:
Parathyroid Hormone - Raises blood calcium level by promoting Osteoclast activity
✔✔Summer Wood - ✔✔Describes secondary growth. Xylem have thicker cell walls and
a smaller radius, which reduces water flow but provides increased support.
✔✔Spring Wood - ✔✔Describes secondary growth. Xylem have thinner cell walls and a
smaller radius, which improves water flow.
✔✔Short Day Plants - ✔✔Only flowers if single stretch of dark is longer then critical
length
✔✔Short Night Plants - ✔✔Only flowers if single stretch of light is longer then critical
length
✔✔Heartwood - ✔✔Center of a tree, surrounds the pith, made of old xylem and no
longer transport sap
✔✔Pith - ✔✔Parenchymal cells at center of tree
✔✔Sapwood - ✔✔Xylem cells surrounding the heartwood that can transport sap
✔✔Vascular Cambium - ✔✔Surround the sapwood, plants version of stem cells that
generate the secondary xylem and phloem
✔✔Vascular Rays - ✔✔Parenchymal cells that get produced with vascular tissue,
appear as straight lines due to the stable production of such cells by certain parts of the
vascular cambium
✔✔Palisade Mesophyll - ✔✔located above spongy mesophyll
✔✔Spongy Mesophyll - ✔✔located below Palisade Mesophyll, loose structure allows
movement of in taken gases
✔✔Guard Cells - ✔✔Two guard cells make a stomata, due to an influx in K+ water
enters the guard cells making them rigid and opening the stomata
GRADED A+
✔✔RAAS - ✔✔realeased by Juxtaglomerular Apparatus in Kidney, Renin-Angiotensin-
Aldosterone-System, creates angiotensin II which stimulates adrenal glands to produce
aldosterone which increases Na+ reabsorption in the distal convoluted tube.
✔✔ANP - ✔✔Atrial Natriuretic Peptide, released in the walls of the atrial chamber in
response to high blood pressure, prevents NaCl reabsorbtion
✔✔ADH - ✔✔Anti Diuretic Hormone, temporally increases the amount of aquaporins in
the walls if the collect duct cells.
✔✔paracrine - ✔✔Hormone acts near secreting cell (ie. Histamine)
✔✔endocrine - ✔✔Hormone acts far from secreting cell, through blood stream (ie.
insulin)
✔✔Nitric Oxide (NO) - ✔✔Paracrine hormone released by epithelial cells when they
receive inadequate O2, signals vasodialation.
✔✔Thyroid Gland Hormones - ✔✔located in neck, releases:
T3 and T4 - Which regulated metabolic processes and include iodine
Calcitonin - Lowers blood calcium by stimulation Osteoblasts to deposit calcium in the
bone
✔✔Pineal Gland Hormones - ✔✔Located in Brain, secretes:
Melatonin - Controls Circadian Rhythm
✔✔Hypothalamus - ✔✔Located in midbrain, secretes:
Oxytocin - Positive feedback loop of birth
ADH - Promotes water reabsorbtion in Kidneys
✔✔Anterior Pituitary Hormones - ✔✔Located in Brain, secretes:
Follicle Stimulating Hormone and Luteinizing Hormone - Which promote the production
of gametes
Thyroid Stimulating Hormone - Stimulates Thyroid to produce T3 and T4
Andrenocorticotropic Hormone - Stimulates Adrenal Cortex
, Prolactin - Stimulates Mammary Glands
Growth Hormone - Promotes growth
✔✔Parathyroid Hormones - ✔✔Located in neck, little nodule attached to Thyroid:
Parathyroid Hormone - Raises blood calcium level by promoting Osteoclast activity
✔✔Summer Wood - ✔✔Describes secondary growth. Xylem have thicker cell walls and
a smaller radius, which reduces water flow but provides increased support.
✔✔Spring Wood - ✔✔Describes secondary growth. Xylem have thinner cell walls and a
smaller radius, which improves water flow.
✔✔Short Day Plants - ✔✔Only flowers if single stretch of dark is longer then critical
length
✔✔Short Night Plants - ✔✔Only flowers if single stretch of light is longer then critical
length
✔✔Heartwood - ✔✔Center of a tree, surrounds the pith, made of old xylem and no
longer transport sap
✔✔Pith - ✔✔Parenchymal cells at center of tree
✔✔Sapwood - ✔✔Xylem cells surrounding the heartwood that can transport sap
✔✔Vascular Cambium - ✔✔Surround the sapwood, plants version of stem cells that
generate the secondary xylem and phloem
✔✔Vascular Rays - ✔✔Parenchymal cells that get produced with vascular tissue,
appear as straight lines due to the stable production of such cells by certain parts of the
vascular cambium
✔✔Palisade Mesophyll - ✔✔located above spongy mesophyll
✔✔Spongy Mesophyll - ✔✔located below Palisade Mesophyll, loose structure allows
movement of in taken gases
✔✔Guard Cells - ✔✔Two guard cells make a stomata, due to an influx in K+ water
enters the guard cells making them rigid and opening the stomata
