BIOL251 HUMAN ANATOMY & PHYSIOLOGY I W/LAB 2026 | MODULE 7 EXAM REVIEW 100+ QUESTIONS AND CORRECT ANSWERS WITH RATIONALE

BIOL251 HUMAN ANATOMY & PHYSIOLOGY
I W/LAB 2026 | MODULE 7 EXAM REVIEW
100+ QUESTIONS AND CORRECT ANSWERS
WITH RATIONALE




SECTION 1: THE ENDOCRINE SYSTEM – OVERVIEW &
HORMONE CLASSIFICATION

1. Which of the following best describes the primary
difference between endocrine and exocrine glands?

 A) Endocrine glands secrete into ducts; exocrine glands
secrete into blood

 B) Endocrine glands secrete hormones into the
bloodstream; exocrine glands secrete products into ducts

 C) Endocrine glands are always unicellular; exocrine
glands are always multicellular

 D) Exocrine glands only secrete enzymes; endocrine
glands only secrete proteins

Correct Answer: B

,Rationale: Endocrine glands are ductless and release
hormones directly into the interstitial fluid and bloodstream
for body-wide distribution. Exocrine glands secrete their
products (e.g., sweat, enzymes, mucus) through ducts onto
epithelial surfaces. This fundamental distinction is critical for
understanding hormone function and regulation .



2. Which of the following is NOT a characteristic of
hormones?

 A) They are chemical messengers

 B) They are secreted by endocrine glands

 C) They are transported via the blood

 D) They act specifically on all cells equally

Correct Answer: D

Rationale: Hormones are specific chemical messengers that
only affect target cells with appropriate receptors. They do
not act on all cells equally—this specificity is a defining
feature of hormonal signaling. This concept is central to
understanding hormone mechanisms of action .



3. Amino acid-based hormones are classified as:

,  A) Lipid-soluble

 B) Water-soluble

 C) Steroid hormones

 D) Derived from cholesterol

Correct Answer: B

Rationale: Amino acid-based hormones (including proteins,
peptides, and amines) are water-soluble and cannot easily
cross the plasma membrane. They bind to cell surface
receptors and initiate intracellular signaling cascades via
second messengers. This distinguishes them from lipid-soluble
steroid hormones .



4. Which of the following hormones is lipid-soluble?

 A) Insulin

 B) Epinephrine

 C) Cortisol

 D) Growth hormone

Correct Answer: C

Rationale: Cortisol is a steroid hormone derived from
cholesterol, making it lipid-soluble. Lipid-soluble hormones can

, cross the plasma membrane and bind to intracellular
receptors, directly affecting gene transcription. Insulin,
epinephrine, and growth hormone are all water-soluble peptide
or amine hormones .



5. Lipid-soluble hormones typically exert their effects by:

 A) Activating G proteins on the cell surface

 B) Directly entering the cell and altering gene expression

 C) Opening ion channels in the plasma membrane

 D) Triggering a cascade of second messengers

Correct Answer: B

Rationale: Lipid-soluble hormones (steroid and thyroid
hormones) diffuse through the plasma membrane and bind to
intracellular receptors, often in the nucleus. The hormone-
receptor complex then acts as a transcription factor, directly
altering gene expression. This is a slower but more prolonged
mechanism compared to water-soluble hormones .



6. Water-soluble hormones exert their effects by:

 A) Diffusing through the plasma membrane