,BIOL 102 Module 5 | Essential Biology II w/Lab
Exam Q&A | Portage Learning
1. Which term describes the functional units of the nervous system that transmit
electrical and chemical signals?
A) Neuroglia
B) Neurons
C) Myocytes
D) Osteocytes
Correct Answer: Neurons
Rationale: Neurons are the excitable cells that generate and transmit electrical
impulses and release neurotransmitters at synapses. Neuroglia support and
protect neurons but do not conduct action potentials in the same way, and
myocytes and osteocytes are muscle and bone cells, respectively.
2. Which neuronal structure receives incoming synaptic signals and conducts
graded potentials toward the cell body?
A) Axon
B) Dendrite
C) Axon terminal
D) Myelin sheath
Correct Answer: Dendrite
,Rationale: Dendrites are branched processes that receive synaptic inputs and
carry graded potentials toward the soma. The axon conducts action potentials
away from the cell body, the axon terminal releases neurotransmitter, and myelin
insulates the axon.
3. What is the primary role of the axon in a neuron?
A) To receive synaptic inputs
B) To synthesize neurotransmitters
C) To conduct action potentials away from the cell body
D) To store genetic information
Correct Answer: To conduct action potentials away from the cell body
Rationale: The axon is a single process that transmits action potentials from the
axon hillock to the axon terminals. Dendrites receive inputs, neurotransmitter
synthesis occurs in the soma, and the nucleus stores genetic information.
4. In the peripheral nervous system, which glial cells form the myelin sheath
around axons?
A) Oligodendrocytes
B) Astrocytes
C) Schwann cells
D) Microglia
Correct Answer: Schwann cells
, Rationale: Schwann cells wrap around peripheral axons to form myelin,
increasing conduction velocity. Oligodendrocytes myelinate central axons,
astrocytes regulate the extracellular environment, and microglia are immune cells.
5. Which glial cell type myelinates axons in the central nervous system?
A) Schwann cells
B) Ependymal cells
C) Satellite cells
D) Oligodendrocytes
Correct Answer: Oligodendrocytes
Rationale: Oligodendrocytes extend processes that wrap around multiple central
axons, forming myelin. Schwann cells myelinate peripheral axons, ependymal cells
line ventricles and produce cerebrospinal fluid, and satellite cells surround
peripheral ganglia.
6. The nodes of Ranvier are important because they:
A) Increase membrane capacitance
B) Synthesize myelin
C) Allow saltatory conduction of action potentials
D) Release neurotransmitters
Correct Answer: Allow saltatory conduction of action potentials
Exam Q&A | Portage Learning
1. Which term describes the functional units of the nervous system that transmit
electrical and chemical signals?
A) Neuroglia
B) Neurons
C) Myocytes
D) Osteocytes
Correct Answer: Neurons
Rationale: Neurons are the excitable cells that generate and transmit electrical
impulses and release neurotransmitters at synapses. Neuroglia support and
protect neurons but do not conduct action potentials in the same way, and
myocytes and osteocytes are muscle and bone cells, respectively.
2. Which neuronal structure receives incoming synaptic signals and conducts
graded potentials toward the cell body?
A) Axon
B) Dendrite
C) Axon terminal
D) Myelin sheath
Correct Answer: Dendrite
,Rationale: Dendrites are branched processes that receive synaptic inputs and
carry graded potentials toward the soma. The axon conducts action potentials
away from the cell body, the axon terminal releases neurotransmitter, and myelin
insulates the axon.
3. What is the primary role of the axon in a neuron?
A) To receive synaptic inputs
B) To synthesize neurotransmitters
C) To conduct action potentials away from the cell body
D) To store genetic information
Correct Answer: To conduct action potentials away from the cell body
Rationale: The axon is a single process that transmits action potentials from the
axon hillock to the axon terminals. Dendrites receive inputs, neurotransmitter
synthesis occurs in the soma, and the nucleus stores genetic information.
4. In the peripheral nervous system, which glial cells form the myelin sheath
around axons?
A) Oligodendrocytes
B) Astrocytes
C) Schwann cells
D) Microglia
Correct Answer: Schwann cells
, Rationale: Schwann cells wrap around peripheral axons to form myelin,
increasing conduction velocity. Oligodendrocytes myelinate central axons,
astrocytes regulate the extracellular environment, and microglia are immune cells.
5. Which glial cell type myelinates axons in the central nervous system?
A) Schwann cells
B) Ependymal cells
C) Satellite cells
D) Oligodendrocytes
Correct Answer: Oligodendrocytes
Rationale: Oligodendrocytes extend processes that wrap around multiple central
axons, forming myelin. Schwann cells myelinate peripheral axons, ependymal cells
line ventricles and produce cerebrospinal fluid, and satellite cells surround
peripheral ganglia.
6. The nodes of Ranvier are important because they:
A) Increase membrane capacitance
B) Synthesize myelin
C) Allow saltatory conduction of action potentials
D) Release neurotransmitters
Correct Answer: Allow saltatory conduction of action potentials
