ADVANCED HUMAN ANATOMY AND
PHYSIOLOGY I (BIO 201) QUESTIONS
WITH CORRECT ANSWERS (LATEST
), (A+ GUARANTEE).
1. Which of the following best describes the molecular mechanism of the absolute refractory
period in a neuron?
A. Voltage-gated potassium channels are open, causing hyperpolarization.
B. The activation gates of voltage-gated sodium channels are closed but can be stimulated.
C. The inactivation gates of voltage-gated sodium channels are closed and cannot be
reopened.
D. The sodium-potassium pump is working at maximum capacity to restore gradients.
Answer: C
Conceptual Explanation: The absolute refractory period occurs because voltage-gated
sodium channels are in an inactivated state (inactivation gate closed), preventing any
further depolarization regardless of stimulus strength.
2. During skeletal muscle contraction, which specific region of the sarcomere remains
constant in length?
A. The A-band
,B. The H-zone
C. The I-band
D. The distance between Z-discs
Answer: A
Conceptual Explanation: The A-band represents the entire length of the thick (myosin)
filaments, which do not change length during contraction; the I-band and H-zone shorten.
3. Which glial cell is responsible for forming the blood-brain barrier by wrapping its
perivascular feet around capillaries?
A. Astrocytes
B. Microglia
C. Ependymal cells
D. Oligodendrocytes
Answer: A
Conceptual Explanation: Astrocytes facilitate the blood-brain barrier by inducing tight
junction formation in endothelial cells via their perivascular feet.
4. In bone remodeling, which hormone is primary in stimulating osteoclast activity when
blood calcium levels drop?
A. Parathyroid Hormone (PTH)
B. Thyroxine
, C. Calcitonin
D. Insulin-like growth factor
Answer: A
Conceptual Explanation: PTH is released by the parathyroid glands in response to low
blood calcium, stimulating osteoclasts to resorb bone matrix and release calcium into the
blood.
5. What is the primary function of the nucleolus within a eukaryotic cell?
A. DNA replication
B. Synthesis of ribosomal RNA (rRNA) and assembly of ribosome subunits
C. Protein folding and modification
D. ATP production via oxidative phosphorylation
Answer: B
Conceptual Explanation: The nucleolus is a dense region in the nucleus where rRNA is
transcribed and combined with proteins to form ribosomal subunits.
6. Which type of epithelial tissue is uniquely designed for stretch and distension, found in the
urinary bladder?
A. Stratified squamous epithelium
B. Pseudostratified columnar epithelium
C. Transitional epithelium
PHYSIOLOGY I (BIO 201) QUESTIONS
WITH CORRECT ANSWERS (LATEST
), (A+ GUARANTEE).
1. Which of the following best describes the molecular mechanism of the absolute refractory
period in a neuron?
A. Voltage-gated potassium channels are open, causing hyperpolarization.
B. The activation gates of voltage-gated sodium channels are closed but can be stimulated.
C. The inactivation gates of voltage-gated sodium channels are closed and cannot be
reopened.
D. The sodium-potassium pump is working at maximum capacity to restore gradients.
Answer: C
Conceptual Explanation: The absolute refractory period occurs because voltage-gated
sodium channels are in an inactivated state (inactivation gate closed), preventing any
further depolarization regardless of stimulus strength.
2. During skeletal muscle contraction, which specific region of the sarcomere remains
constant in length?
A. The A-band
,B. The H-zone
C. The I-band
D. The distance between Z-discs
Answer: A
Conceptual Explanation: The A-band represents the entire length of the thick (myosin)
filaments, which do not change length during contraction; the I-band and H-zone shorten.
3. Which glial cell is responsible for forming the blood-brain barrier by wrapping its
perivascular feet around capillaries?
A. Astrocytes
B. Microglia
C. Ependymal cells
D. Oligodendrocytes
Answer: A
Conceptual Explanation: Astrocytes facilitate the blood-brain barrier by inducing tight
junction formation in endothelial cells via their perivascular feet.
4. In bone remodeling, which hormone is primary in stimulating osteoclast activity when
blood calcium levels drop?
A. Parathyroid Hormone (PTH)
B. Thyroxine
, C. Calcitonin
D. Insulin-like growth factor
Answer: A
Conceptual Explanation: PTH is released by the parathyroid glands in response to low
blood calcium, stimulating osteoclasts to resorb bone matrix and release calcium into the
blood.
5. What is the primary function of the nucleolus within a eukaryotic cell?
A. DNA replication
B. Synthesis of ribosomal RNA (rRNA) and assembly of ribosome subunits
C. Protein folding and modification
D. ATP production via oxidative phosphorylation
Answer: B
Conceptual Explanation: The nucleolus is a dense region in the nucleus where rRNA is
transcribed and combined with proteins to form ribosomal subunits.
6. Which type of epithelial tissue is uniquely designed for stretch and distension, found in the
urinary bladder?
A. Stratified squamous epithelium
B. Pseudostratified columnar epithelium
C. Transitional epithelium
