Bio 121 Test Questions with Correct
Answers
The axon hillock of a neuron is considered the: - ANSWER-Triggering zone
What is a false statement regarding graded potentials? - ANSWER-They are self
propagating
What is an incorrect description of a graded potential? - ANSWER-It has a refractory
period
If a neuron were experimentally stimulated at both ends simultaneously: - ANSWER-
The action potentials would stop as they met in the middle
An action potential develops when: - ANSWER--Threshold potential is reached
-Summation of graded potentials occurs to a great enough extent
-Rapid depolarization of the axon occurs
Action potentials: - ANSWER-Occur only when the membrane is depolarized to the
threshold potential
What is an incorrect statement about the action potential? - ANSWER-It speeds up
transmission by summation
A threshold potential is: - ANSWER-The point at which there is an explosive increase
in membrane permeability to Na+
Why is the axolemma a specialized cell membrane? - ANSWER-It contains more
sodium and potassium channels than other cell types
The nodes of Ranvier: - ANSWER--Contain large concentrations of voltage gated
Na+ and K+ channels
-Are used in salutatory conduction of action potentials
-Occur between internodes of myelin
A stronger triggering event: - ANSWER-Increases the frequency of action potentials
along the axon
Saltatory conduction: - ANSWER-Involves the impulse jumping from one node of
Ranvier to the adjacent node
Multiple sclerosis is a demyelinating disease that affects the myelin of the spinal
cord. What symptoms might be indicative of such a disease? - ANSWER-The patient
would have slower reflexes due to using more contiguous nerve conduction
, Directly following an action potential, the Na+/K+ pump must: - ANSWER-Only
needs to operate every few action potentials due to the large amounts of ions
present in ICF and ECF of excitable tissues
What would result if the Na+/K+ pump was inhibited? - ANSWER-The membrane
would lose polarity
Hyperpolarization results from: - ANSWER-Potassium moving out of the cell
Which of the following is involved with a positive feedback cycle? - ANSWER-
Voltage gated Na+ channels
Body temperature: - ANSWER-Controlled variable
Temperature-sensetive nerve cells: - ANSWER-Sensor
Skeletal muscles and sweat glands: - ANSWER-Effector
Hypothalamus: - ANSWER-Integrator or control center
Cells are made up of a lot of molecules, except: - ANSWER-Minerals
The number of ATP molecules produced under anaerobic conditions from one
molecule of glucose is: - ANSWER-2
What is the correct order of cellular respiration from glucose of processes in an
aerobic environment? - ANSWER-Glycolysis, Kreb's cycle, electron transport chain
What function is associated with the rough endoplasmic reticulum? - ANSWER-
Protein synthesis
The phospholipids within the plasma membrane: - ANSWER--Form a bilayer with the
non polar tails buried in the center and the hydrophilic heads lined up on the outer
and inner surfaces
-Serve as a barrier to passage of water-soluble substances between the ICF and
ECF
The plasma membrane: - ANSWER--Appears trilaminar under an electron
microscope
-Is composed primarily of a lipid bilayer with proteins interspersed throughout the
phospholipids in a mosaic fashion
-Is more permeable to K+ than to Na+ at a resting state
-Contains cholesterol
What properties influence the cellular permeability of a particle? - ANSWER--
Solubility of the particle in lipid
-Size of particle
Charged and polar molecules: - ANSWER-Are typically water soluble solutes
Answers
The axon hillock of a neuron is considered the: - ANSWER-Triggering zone
What is a false statement regarding graded potentials? - ANSWER-They are self
propagating
What is an incorrect description of a graded potential? - ANSWER-It has a refractory
period
If a neuron were experimentally stimulated at both ends simultaneously: - ANSWER-
The action potentials would stop as they met in the middle
An action potential develops when: - ANSWER--Threshold potential is reached
-Summation of graded potentials occurs to a great enough extent
-Rapid depolarization of the axon occurs
Action potentials: - ANSWER-Occur only when the membrane is depolarized to the
threshold potential
What is an incorrect statement about the action potential? - ANSWER-It speeds up
transmission by summation
A threshold potential is: - ANSWER-The point at which there is an explosive increase
in membrane permeability to Na+
Why is the axolemma a specialized cell membrane? - ANSWER-It contains more
sodium and potassium channels than other cell types
The nodes of Ranvier: - ANSWER--Contain large concentrations of voltage gated
Na+ and K+ channels
-Are used in salutatory conduction of action potentials
-Occur between internodes of myelin
A stronger triggering event: - ANSWER-Increases the frequency of action potentials
along the axon
Saltatory conduction: - ANSWER-Involves the impulse jumping from one node of
Ranvier to the adjacent node
Multiple sclerosis is a demyelinating disease that affects the myelin of the spinal
cord. What symptoms might be indicative of such a disease? - ANSWER-The patient
would have slower reflexes due to using more contiguous nerve conduction
, Directly following an action potential, the Na+/K+ pump must: - ANSWER-Only
needs to operate every few action potentials due to the large amounts of ions
present in ICF and ECF of excitable tissues
What would result if the Na+/K+ pump was inhibited? - ANSWER-The membrane
would lose polarity
Hyperpolarization results from: - ANSWER-Potassium moving out of the cell
Which of the following is involved with a positive feedback cycle? - ANSWER-
Voltage gated Na+ channels
Body temperature: - ANSWER-Controlled variable
Temperature-sensetive nerve cells: - ANSWER-Sensor
Skeletal muscles and sweat glands: - ANSWER-Effector
Hypothalamus: - ANSWER-Integrator or control center
Cells are made up of a lot of molecules, except: - ANSWER-Minerals
The number of ATP molecules produced under anaerobic conditions from one
molecule of glucose is: - ANSWER-2
What is the correct order of cellular respiration from glucose of processes in an
aerobic environment? - ANSWER-Glycolysis, Kreb's cycle, electron transport chain
What function is associated with the rough endoplasmic reticulum? - ANSWER-
Protein synthesis
The phospholipids within the plasma membrane: - ANSWER--Form a bilayer with the
non polar tails buried in the center and the hydrophilic heads lined up on the outer
and inner surfaces
-Serve as a barrier to passage of water-soluble substances between the ICF and
ECF
The plasma membrane: - ANSWER--Appears trilaminar under an electron
microscope
-Is composed primarily of a lipid bilayer with proteins interspersed throughout the
phospholipids in a mosaic fashion
-Is more permeable to K+ than to Na+ at a resting state
-Contains cholesterol
What properties influence the cellular permeability of a particle? - ANSWER--
Solubility of the particle in lipid
-Size of particle
Charged and polar molecules: - ANSWER-Are typically water soluble solutes
