WGU D203 Fundamentals of Anatomy and Physiology: Exam 2
50 questions
1. Why does a positive feedback loop not usually maintain homeostasis?
A. It always restores balance
B. It never occurs in the body
C. It only works in plants
D. It amplifies change until a specific event ends it, rather than restoring a set point
Correct Answer: D. It amplifies change until a specific event ends it, rather than restoring a
set point
Rationale: Most homeostatic control is negative feedback.
2. A patient's blood glucose rises after a meal. Which sequence correctly describes the negative
feedback response?
A. Alpha cells release glucagon, glucose rises further
B. Beta cells detect high glucose, release insulin, cells take up glucose, glucose falls
C. The liver releases more glucose
D. The adrenal gland releases cortisol to raise glucose
Correct Answer: B. Beta cells detect high glucose, release insulin, cells take up glucose,
glucose falls
Rationale: Insulin lowers blood glucose.
3. Why does a cell with many mitochondria likely belong to muscle tissue?
A. Muscle cells store fat
B. Mitochondria produce proteins
C. Muscle cells need large amounts of ATP for contraction
D. Muscle cells lack energy needs
Correct Answer: C. Muscle cells need large amounts of ATP for contraction
Rationale: Structure reflects function.
4. Why do intravenous fluids need to be isotonic for routine use?
A. To increase cell size
B. To dehydrate cells
C. To avoid shrinking or bursting blood cells
D. To kill bacteria
Correct Answer: C. To avoid shrinking or bursting blood cells
Rationale: Tonicity determines water movement.
5. Why can oxygen cross the plasma membrane easily but glucose cannot?
A. Glucose is a gas
B. Oxygen requires ATP
C. The membrane blocks all gases
D. Oxygen is small and nonpolar; glucose is larger and polar and needs carrier proteins
Correct Answer: D. Oxygen is small and nonpolar; glucose is larger and polar and needs
carrier proteins
Rationale: Glucose uses facilitated diffusion.
, 6. Why is simple squamous epithelium found in alveoli and capillaries?
A. Its thin, flat cells allow rapid diffusion
B. It provides protection from abrasion
C. It secretes mucus
D. It contracts
Correct Answer: A. Its thin, flat cells allow rapid diffusion
Rationale: Thin barriers speed exchange.
7. Why do cartilage injuries heal slowly?
A. Cartilage is avascular, receiving nutrients by diffusion
B. Cartilage has many blood vessels
C. Cartilage regenerates quickly
D. Cartilage contains nerves
Correct Answer: A. Cartilage is avascular, receiving nutrients by diffusion
Rationale: Limited blood supply slows repair.
8. Why does skin turn pale in a cold environment?
A. Melanin decreases
B. Sweat increases
C. Dermal blood vessels constrict to conserve heat
D. Epidermis thickens
Correct Answer: C. Dermal blood vessels constrict to conserve heat
Rationale: Vasoconstriction reduces heat loss.
9. Why are full-thickness burns at risk for infection and fluid loss?
A. They are superficial
B. The protective barrier of skin is destroyed
C. Sweat glands increase
D. Blood vessels become stronger
Correct Answer: B. The protective barrier of skin is destroyed
Rationale: Skin normally prevents water loss and microbial entry.
10. Why do children's long bones lengthen but adults' do not?
A. Children have active epiphyseal plates that close after puberty
B. Adults lack osteoblasts
C. Children's bones lack calcium
D. Adults have more cartilage
Correct Answer: A. Children have active epiphyseal plates that close after puberty
Rationale: Plates become epiphyseal lines.
11. Why does a lack of vitamin D lead to weak bones?
A. Osteoclasts stop working
B. Calcium absorption from the gut decreases
C. Bones gain too much calcium
D. Collagen production increases
Correct Answer: B. Calcium absorption from the gut decreases
Rationale: Vitamin D is needed for calcium uptake.
50 questions
1. Why does a positive feedback loop not usually maintain homeostasis?
A. It always restores balance
B. It never occurs in the body
C. It only works in plants
D. It amplifies change until a specific event ends it, rather than restoring a set point
Correct Answer: D. It amplifies change until a specific event ends it, rather than restoring a
set point
Rationale: Most homeostatic control is negative feedback.
2. A patient's blood glucose rises after a meal. Which sequence correctly describes the negative
feedback response?
A. Alpha cells release glucagon, glucose rises further
B. Beta cells detect high glucose, release insulin, cells take up glucose, glucose falls
C. The liver releases more glucose
D. The adrenal gland releases cortisol to raise glucose
Correct Answer: B. Beta cells detect high glucose, release insulin, cells take up glucose,
glucose falls
Rationale: Insulin lowers blood glucose.
3. Why does a cell with many mitochondria likely belong to muscle tissue?
A. Muscle cells store fat
B. Mitochondria produce proteins
C. Muscle cells need large amounts of ATP for contraction
D. Muscle cells lack energy needs
Correct Answer: C. Muscle cells need large amounts of ATP for contraction
Rationale: Structure reflects function.
4. Why do intravenous fluids need to be isotonic for routine use?
A. To increase cell size
B. To dehydrate cells
C. To avoid shrinking or bursting blood cells
D. To kill bacteria
Correct Answer: C. To avoid shrinking or bursting blood cells
Rationale: Tonicity determines water movement.
5. Why can oxygen cross the plasma membrane easily but glucose cannot?
A. Glucose is a gas
B. Oxygen requires ATP
C. The membrane blocks all gases
D. Oxygen is small and nonpolar; glucose is larger and polar and needs carrier proteins
Correct Answer: D. Oxygen is small and nonpolar; glucose is larger and polar and needs
carrier proteins
Rationale: Glucose uses facilitated diffusion.
, 6. Why is simple squamous epithelium found in alveoli and capillaries?
A. Its thin, flat cells allow rapid diffusion
B. It provides protection from abrasion
C. It secretes mucus
D. It contracts
Correct Answer: A. Its thin, flat cells allow rapid diffusion
Rationale: Thin barriers speed exchange.
7. Why do cartilage injuries heal slowly?
A. Cartilage is avascular, receiving nutrients by diffusion
B. Cartilage has many blood vessels
C. Cartilage regenerates quickly
D. Cartilage contains nerves
Correct Answer: A. Cartilage is avascular, receiving nutrients by diffusion
Rationale: Limited blood supply slows repair.
8. Why does skin turn pale in a cold environment?
A. Melanin decreases
B. Sweat increases
C. Dermal blood vessels constrict to conserve heat
D. Epidermis thickens
Correct Answer: C. Dermal blood vessels constrict to conserve heat
Rationale: Vasoconstriction reduces heat loss.
9. Why are full-thickness burns at risk for infection and fluid loss?
A. They are superficial
B. The protective barrier of skin is destroyed
C. Sweat glands increase
D. Blood vessels become stronger
Correct Answer: B. The protective barrier of skin is destroyed
Rationale: Skin normally prevents water loss and microbial entry.
10. Why do children's long bones lengthen but adults' do not?
A. Children have active epiphyseal plates that close after puberty
B. Adults lack osteoblasts
C. Children's bones lack calcium
D. Adults have more cartilage
Correct Answer: A. Children have active epiphyseal plates that close after puberty
Rationale: Plates become epiphyseal lines.
11. Why does a lack of vitamin D lead to weak bones?
A. Osteoclasts stop working
B. Calcium absorption from the gut decreases
C. Bones gain too much calcium
D. Collagen production increases
Correct Answer: B. Calcium absorption from the gut decreases
Rationale: Vitamin D is needed for calcium uptake.
