WGU D313 Anatomy and Physiology II Objective Assessment Questions
(2025/2026)
1.What is the primary role of negative feedback in maintaining homeosta- sis?a)To amplify changes in a physiological variable b)To maintain a variable within a narrow range c)To prevent any change in the bodys internal environment d)To initiate rapid responses to external stimuli
Correct Answer: b) To maintain a variable within a narrow range
Rationale: Negative feedback mechanisms detect deviations from a set
point and initiate responses to return the variable (e.g., body tempera- ture, blood glucose) to its normal range, ensuring stability. Amplification occurs in positive feedback, not negative.
2.Which level of biological organization includes all the chemical reactions occurring in an organism?a)Cellular b)Tissue c)Organ d)Organismal
Correct Answer: d) Organismal
Rationale: The organismal level encompasses all chemical reactions (metabolism)
across cells, tissues, organs, and systems, integrating the entire bodys functions. Lower levels are more specific.
3.How does the body respond to a drop in blood pressure to maintain homeostasis?a)By decreasing heart rate b)By activating the renin-angiotensin-aldosterone system (RAAS) c)By reducing blood volume d)By dilating blood vessels
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Correct Answer: b) By activating the renin-angiotensin-aldosterone sys-
tem (RAAS)
Rationale: A drop in blood pressure triggers the RAAS, which increases
blood volume and vasoconstriction to raise blood pressure. The other options would exacerbate the drop.
4.Which organelle is primarily responsible for ATP production in eukary- otic cells?a)Nucleus b)Mitochondrion c)Golgi apparatus d)Endoplasmic reticulum
Correct Answer: b) Mitochondrion
Rationale: Mitochondria are the powerhouses of the cell, producing
ATP via oxidative phosphorylation during cellular respiration. Other organelles have different primary functions.
5.What type of transport requires energy to move substances against their concentration gradient?a)Simple diffusion b)Facilitated diffusion c)Active transport d)Osmosis
Correct Answer: c) Active transport
Rationale: Active transport uses energy (usually ATP) to move sub-
stances against their gradient, unlike passive processes like diffusion or osmosis.
6.What is the role of the sodium-potassium pump in cells?a)Maintains osmotic balance by pumping water b)Establishes a membrane potential by exchanging ions c)Transports glucose into cells d)Synthesizes proteins for export
Correct Answer: b) Establishes a membrane potential by exchanging
ions
Rationale: The sodium-potassium pump moves 3 Na
+ out and 2 K + into the cell, creating an electrochemical gradient essential for membrane potential and nerve signaling.
7.Which tissue type is characterized by tightly packed cells with minimal extracellular matrix?a)Connective tissue
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