Knpe 125 Unit 1 Test
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- 1.
Which of the following is the correct equation for the physiological flow model?
- A.
Flow=Inflow-Outflow
- B.
Flow = Gradient (P) x Conductance
- C.
Flow = Gradient (P)/Conductance
- D.
Flow = Gradient (P) x Resistance
Correct Answer
B. Flow = Gradient (P) x ConductanceExplanation
The correct equation for the physiological flow model is Flow = Gradient (P) x Conductance. This equation represents the relationship between flow, pressure gradient, and conductance. It states that the flow of a substance is equal to the pressure gradient across a system multiplied by the conductance of that system. Conductance represents the ease with which a substance can flow through a system, and the pressure gradient represents the difference in pressure between two points. Therefore, this equation accurately describes the relationship between flow, pressure, and conductance in the physiological flow model.Rate this question:
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- 2.
Assuming constant high conductance, what would happen to flow of sodium into cell if the pressure of sodium of the cell decreased from 20 to 16 while the pressure of sodium on the inside of the cell decreased from 14 to 4?
- A.
Flow would increase
- B.
Flow would decrease
- C.
Flow would not change
Correct Answer
A. Flow would increaseExplanation
If the pressure of sodium on the outside of the cell decreases while the pressure of sodium on the inside of the cell decreases, it creates a larger concentration gradient. This means that there is a greater difference in the concentration of sodium between the inside and outside of the cell. Since the flow of sodium is driven by this concentration gradient, a larger gradient would result in an increased flow of sodium into the cell. Therefore, the correct answer is that the flow would increase.Rate this question:
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- 3.
Identify the example below that represents an increase in conductance
- A.
Placing an NFL lineman in the doorway and telling him to stop people from entering
- B.
A highway decreasing lanes of traffic from 3 to 1
- C.
Increasing the number of bouncers at the front doors to a bar
- D.
The number of people trying to enter a building doubling from 250 to 500
Correct Answer
C. Increasing the number of bouncers at the front doors to a barExplanation
Increasing the number of bouncers at the front doors to a bar represents an increase in conductance. Conductance refers to the ease with which a current can flow through a conductor. In this case, the bouncers act as conductors, controlling the flow of people entering the bar. By increasing the number of bouncers, the conductance of people entering the bar increases because more people can be accommodated and allowed in at a faster rate.Rate this question:
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- 4.
If the mass, or pool, of substance y is increasing, which of the following is likely to be true?
- A.
P for inflow is decreasing
- B.
P for outflow is increase
- C.
Conductance for inflow is increasing
- D.
Conductance for outflow is increasing
- E.
None of the above would be expected to accompany an increase in the mass of substance y.
Correct Answer
C. Conductance for inflow is increasingExplanation
If the mass of substance y is increasing, it means that more of substance y is entering the system. In order for more substance y to enter the system, the conductance for inflow must be increasing. This implies that there is a higher rate of flow or easier movement of substance y into the system. The other options, such as P for inflow decreasing or P for outflow increasing, do not necessarily indicate an increase in the mass of substance y.Rate this question:
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- 5.
Which of the following is the major difference between feedback and feed forward control?
- A.
Only feedback control alters regulated variables
- B.
Only feed forward control alters regulated variables
- C.
Only feedback control utilizes a controller
- D.
Only feedback control directly responds to changes in regulated variables
Correct Answer
D. Only feedback control directly responds to changes in regulated variablesExplanation
Feedback control directly responds to changes in regulated variables, while feed forward control does not. Feedback control continuously monitors the regulated variables and makes adjustments based on the feedback received. It compares the actual output to the desired output and makes changes accordingly. On the other hand, feed forward control does not directly respond to changes in regulated variables. It predicts the changes based on known factors and adjusts the control accordingly, without directly monitoring the regulated variables.Rate this question:
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- 6.
Which of the physiological models presented in KNPE 125 do not contribute significantly to the events between two neurons that lead to depolarization of the post-synaptic neuron?
- A.
Model of flow
- B.
Conservation of mass model
- C.
Receptor Mediated Signalling
- D.
None of the above models are involved
- E.
All of the above models are involved
Correct Answer
D. None of the above models are involvedExplanation
The correct answer is "None of the above models are involved." This means that all of the physiological models presented in KNPE 125 contribute significantly to the events between two neurons that lead to depolarization of the post-synaptic neuron.Rate this question:
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- 7.
Of the following examples, only ______ could be defined as exergonic
- A.
Breaking down ATP (ATP Hydrolysis)
- B.
Producing ATP (ATP synthesis)
- C.
Lighting a match
- D.
Both a and c are exergonic
- E.
Both b and c are exergonic
Correct Answer
D. Both a and c are exergonicExplanation
Both breaking down ATP (ATP hydrolysis) and lighting a match can be defined as exergonic processes. Exergonic reactions release energy as they proceed, and both of these examples involve the release of energy. Breaking down ATP releases energy that can be used by cells for various functions, while lighting a match involves the release of energy in the form of heat and light.Rate this question:
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- 8.
Which of the following reactions would typically require the most activation energy
- A.
Exergonic
- B.
Exergonic reactions catalyzed by an enzyme
- C.
Endergonic
- D.
Endergonic reaction catalyzed by an enzyme
- E.
All of these reactions typically require the same amount of activation energy
Correct Answer
C. EndergonicExplanation
Endergonic reactions typically require the most activation energy because they involve the formation of new bonds and the input of energy to proceed. In an endergonic reaction, the products have higher energy than the reactants, and this energy difference needs to be overcome by providing activation energy. On the other hand, exergonic reactions release energy as they proceed, making them more favorable and requiring less activation energy. The presence of an enzyme can lower the activation energy for both exergonic and endergonic reactions, but endergonic reactions still generally require more activation energy compared to exergonic reactions.Rate this question:
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- 9.
Which of the following is true regarding enzyme function
- A.
Enzymes change chemical reactions from exergonic to endergonic.
- B.
Enzymes speed the rate of a reaction by increasing availability of substrate
- C.
Enzymes speed the rate of a reaction by increasing activation energy
- D.
Each individual enzyme is a small protein that speeds the rate of a wide range of chemical reactions
- E.
None of the above is true
Correct Answer
E. None of the above is trueExplanation
Enzymes are biological catalysts that speed up chemical reactions by lowering the activation energy required for the reaction to occur. They do not change the nature of the reaction from exergonic to endergonic. Additionally, enzymes do not increase the availability of substrate, but rather increase the rate at which substrate molecules are converted into products. While enzymes are often proteins, not all enzymes are small proteins, and they may catalyze specific reactions rather than a wide range of reactions. Therefore, none of the statements given in the options are true.Rate this question:
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- 10.
Which of the following would decrease the rate of the reaction
- A.
Increasing the number of products
- B.
Decreasing the number of enzymes
- C.
Decreasing the number of substrates
- D.
All of the above
- E.
None of the Above
Correct Answer
D. All of the aboveExplanation
Increasing the number of products would decrease the rate of the reaction because it would cause a shift in the equilibrium towards the reactants, slowing down the forward reaction. Decreasing the number of enzymes would also decrease the rate of the reaction because enzymes act as catalysts, speeding up the reaction by lowering the activation energy. Finally, decreasing the number of substrates would decrease the rate of the reaction because there would be fewer reactant molecules available to participate in the reaction. Therefore, all of these factors would contribute to a decrease in the reaction rate.Rate this question:
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- 11.
When an enzyme is “saturated”, the number of substrate present Is _____ the number of enzymes
- A.
Less than
- B.
Equal to
- C.
Greater than
- D.
Both a and b
- E.
Both b and c
Correct Answer
E. Both b and cExplanation
When an enzyme is "saturated", it means that all the enzyme molecules are already bound to substrate molecules and are actively catalyzing reactions. In this state, the number of substrate molecules present is equal to or greater than the number of enzyme molecules. Therefore, the correct answer is "Both b and c."Rate this question:
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- 12.
Which of the following is/are true regarding membrane structure and function?
- A.
Membranes are made up of phospholipids that have a hydrophilic tail and a hydrophobic head.
- B.
Membranes are impermeable to water soluble substances such as carbohydrates and protein
- C.
Fat soluble substances can only diffuse across a membrane when specific channels or transporters are present
- D.
Both a and b are true
Correct Answer
B. Membranes are impermeable to water soluble substances such as carbohydrates and protein -
- 13.
In which of the following processes do ligand gated channels pay a direct and essential role?
- A.
Conduction of an action potential down an axon
- B.
Release of neurotransmitters from a pre-synaptic neuron
- C.
Initiation of an action potential in a post synaptic neuron
Correct Answer
C. Initiation of an action potential in a post synaptic neuronExplanation
Ligand-gated channels play a direct and essential role in the initiation of an action potential in a post-synaptic neuron. These channels are located on the post-synaptic membrane and are activated by neurotransmitters released from the pre-synaptic neuron. When the neurotransmitter binds to the ligand-gated channels, they open, allowing ions to flow into the post-synaptic neuron. This influx of ions can depolarize the post-synaptic membrane, leading to the initiation of an action potential. Therefore, the correct answer is the initiation of an action potential in a post-synaptic neuron.Rate this question:
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- 14.
If the rate of diffusion for substance z increased linearly with increasing concentration gradient, diffusion of substance z is an example of
- A.
Simple diffusion
- B.
Facilitated Diffusion
- C.
Active Transport
- D.
Co-transport
Correct Answer
A. Simple diffusionExplanation
The given statement suggests that the rate of diffusion for substance z increases linearly with increasing concentration gradient. This characteristic is a key feature of simple diffusion, where substances move across a concentration gradient without the need for any external energy or assistance. In simple diffusion, molecules move freely through the cell membrane from an area of higher concentration to an area of lower concentration until equilibrium is reached. Therefore, based on the information provided, the diffusion of substance z is an example of simple diffusion.Rate this question:
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- 15.
In which of the following types of transport is ATP breakdown directly involved in?
- A.
Active Transport
- B.
Co-Transport
- C.
Counter-Transport
- D.
All of the above directly require the breakdown of ATP
Correct Answer
A. Active TransportExplanation
Active transport is a process that requires the movement of molecules across a cell membrane against their concentration gradient, which requires the expenditure of energy. This energy is provided by the breakdown of ATP (adenosine triphosphate) into ADP (adenosine diphosphate) and inorganic phosphate. Co-transport and counter-transport are specific types of active transport where the movement of one molecule is coupled with the movement of another molecule or ion. Therefore, all of the given options directly involve the breakdown of ATP to fuel the active transport process.Rate this question:
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- 16.
Where does transcription occur
- A.
Cytoplasm
- B.
Endoplasmic Reticulum
- C.
Golgi Apparatus
- D.
Nucleoplasm
Correct Answer
D. NucleoplasmExplanation
Transcription is the process by which genetic information from DNA is copied into RNA. It occurs in the nucleus of eukaryotic cells, specifically in the nucleoplasm. This is where the DNA is located, and it is where the enzyme RNA polymerase binds to the DNA and synthesizes the RNA molecule. The other options, cytoplasm, endoplasmic reticulum, and Golgi apparatus, are not involved in the transcription process.Rate this question:
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- 17.
Which of the following contains the correct order of the events of translation
- A.
Initiation, Elongation, Termination
- B.
Elongation, Initiation, Termination
- C.
Elongation, Termination, Initiation
- D.
Initiation, Termination, Elongation
Correct Answer
A. Initiation, Elongation, TerminationExplanation
The correct order of events in translation is initiation, elongation, and termination. Initiation is the first step in translation where the ribosome binds to the mRNA and the start codon is recognized. Elongation follows initiation, where amino acids are added to the growing polypeptide chain. Termination is the final step, where the ribosome reaches a stop codon and the polypeptide chain is released.Rate this question:
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- 18.
___ type of RNA binds to the 40s subunit, whereas _____ type of RNA brings amino acids to the 60s subunit:
- A.
MRNA; tRNA
- B.
TRNA; rRNA
- C.
RRNA; mRNA
- D.
MRNA; rRNA
Correct Answer
A. MRNA; tRNAExplanation
mRNA binds to the 40s subunit of the ribosome, while tRNA brings amino acids to the 60s subunit. mRNA carries the genetic information from the DNA to the ribosome, where it is used as a template for protein synthesis. tRNA, on the other hand, carries specific amino acids to the ribosome, where they are assembled into a polypeptide chain according to the instructions provided by the mRNA. Therefore, mRNA and tRNA play different roles in the process of protein synthesis.Rate this question:
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- 19.
Which of the following represents the path a newly formed protein would take as it travelled from membrane
- A.
Mitochondria, ER, membrane
- B.
ER, mitochondria, membrane
- C.
ER, Golgi Apparatus, Membrane
- D.
ER, Golgi Apparatus, Mitochondria, Membrane
Correct Answer
C. ER, Golgi Apparatus, MembraneExplanation
The correct answer is ER, Golgi Apparatus, Membrane. This is because newly formed proteins are synthesized in the endoplasmic reticulum (ER), then they are transported to the Golgi Apparatus for modification and sorting, and finally, they are transported to the cell membrane for secretion or integration into the membrane.Rate this question:
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- 20.
Identify the example below that describes how, according to the flow model, exercise training improves performance.
- A.
More enzymes increase substrate availability
- B.
Fewer enzymes decrease substrate availability
- C.
More enzymes increase conductance
- D.
More substance decreases resistance
Correct Answer
A. More enzymes increase substrate availabilityExplanation
According to the flow model, exercise training improves performance by increasing substrate availability through the production of more enzymes. Enzymes play a crucial role in breaking down substrates and converting them into usable energy for the body. By increasing the number of enzymes, exercise training enhances the efficiency of substrate breakdown, leading to improved performance.Rate this question:
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- 21.
What is the difference between the Nernst and Goldman equation?
- A.
Only the Nerst equation considers the electrical charge across a membrane
- B.
Only the Goldman equaiton considers concentration gradients
- C.
Only the Goldman equation takes into consideration membrane permeability
- D.
Only the Nerst equation considers the contribution of the Na+/K+ pump
Correct Answer
C. Only the Goldman equation takes into consideration membrane permeabilityExplanation
The Nernst equation calculates the equilibrium potential for a single ion based on its concentration gradient and electrical charge across a membrane. It does not take into account membrane permeability. On the other hand, the Goldman equation considers both concentration gradients and membrane permeability to calculate the membrane potential. It takes into account the permeability of multiple ions, allowing for a more accurate calculation of the membrane potential. The contribution of the Na+/K+ pump is not considered in either equation.Rate this question:
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- 22.
Which of the following statements is NOT true of “leak” channels as they relate to membrane potential?
- A.
Leak channels allow both Na+ and K+ to diffuse freely across cell membranes
- B.
Leak channels are the main reason that K+ contributes more to membrane potential than Na+
- C.
Leak channels allow 1000 times more Na+ to diffuse than K+
- D.
Leak channels are integral membrane proteins
Correct Answer
C. Leak channels allow 1000 times more Na+ to diffuse than K+Explanation
Leak channels allow both Na+ and K+ to diffuse freely across cell membranes. This means that both Na+ and K+ can move in and out of the cell through these channels. Leak channels are the main reason that K+ contributes more to membrane potential than Na+. This is because there are more leak channels for K+ compared to Na+, allowing K+ to move more freely and therefore have a greater impact on the membrane potential. Leak channels are integral membrane proteins, meaning they are embedded within the cell membrane. However, it is not true that leak channels allow 1000 times more Na+ to diffuse than K+.Rate this question:
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- 23.
Opening a K+ channel located within the membrane of a resting neural cell would cause that neurons membrane potential to become ____.
- A.
More positive
- B.
More negative
- C.
Opening a K+ channel would have no impact on membrane potential
Correct Answer
B. More negativeExplanation
Opening a K+ channel located within the membrane of a resting neural cell would cause that neuron's membrane potential to become more negative. This is because K+ channels are responsible for allowing the outflow of K+ ions from the cell, leading to hyperpolarization of the membrane potential. As more positive ions leave the cell, the inside of the cell becomes more negative, resulting in a decrease in the membrane potential.Rate this question:
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- 24.
During depolarization, the membrane potential becomes more ____ because _____ channels open.
- A.
Positive, Sodium (Na+)
- B.
Positive, Potassium (K+)
- C.
Negative, Sodium (Na+)
- D.
Negative, Potassium (K+)
Correct Answer
A. Positive, Sodium (Na+)Explanation
During depolarization, the membrane potential becomes more positive because sodium (Na+) channels open.Rate this question:
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- 25.
Multiple Sclerosis (MS) is a disease that slowly prevents the nervous system from conducting action potentials. Why does MS have this effect?
- A.
The body’s immune system attacks and damages myelin sheath decreasing the rate of action potential conduction.
- B.
The body’s immune system attacks and damages the myelin sheath increasing the rate of the action potential conduction
- C.
With MS, the nodes of Ranvier are damaged and allow action potentials to diffuse out of the axon stopping conduction
- D.
All of the above are true
- E.
Only a and b are true
Correct Answer
A. The body’s immune system attacks and damages myelin sheath decreasing the rate of action potential conduction.Explanation
In multiple sclerosis (MS), the body's immune system mistakenly attacks and damages the myelin sheath, which is a protective covering around nerve fibers. This damage disrupts the normal flow of electrical impulses along the nerves, leading to a decrease in the rate of action potential conduction. As a result, the nervous system's ability to transmit signals efficiently is compromised, causing the symptoms associated with MS. This answer accurately describes the underlying mechanism of MS.Rate this question:
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- 26.
When an action potential reaches the terminal end of an exon, voltage gated ____ channels open triggering neurotransmitter into the synapse
- A.
Na+
- B.
K=
- C.
Cl-
- D.
Ca2+
Correct Answer
D. Ca2+Explanation
When an action potential reaches the terminal end of an exon, voltage gated Ca2+ channels open triggering neurotransmitter into the synapse. This is because Ca2+ ions play a crucial role in synaptic transmission. The influx of Ca2+ ions into the terminal end of the exon allows for the fusion of neurotransmitter-containing vesicles with the presynaptic membrane, leading to the release of neurotransmitters into the synapse. This triggers the transmission of signals from one neuron to another.Rate this question:
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- 27.
A neurotransmitter can have many different effects on a post-synaptic cell. Which of the following is not one of these effects?
- A.
Depolarization via opening of Na+ channels
- B.
Hyperpolarization via opening of Cl- channels
- C.
Activation of protein synthesis
- D.
All of the above are effects of a neurotransmitter
Correct Answer
D. All of the above are effects of a neurotransmitterExplanation
All of the options listed in the question are effects of a neurotransmitter. Depolarization via opening of Na+ channels and hyperpolarization via opening of Cl- channels are both examples of how a neurotransmitter can affect the electrical state of a post-synaptic cell. Activation of protein synthesis is another effect of a neurotransmitter, as it can trigger the synthesis of new proteins in the cell. Therefore, all of the given options are correct and represent effects of a neurotransmitter.Rate this question:
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- 28.
The statement “the firing of more than one excitatory synapse at the same time results in depolarization that is greater than threshold” best defines which of the following
- A.
Spatial Summation
- B.
Temporal Summation
- C.
Action Potential Threshold
Correct Answer
A. Spatial SummationExplanation
Spatial summation refers to the process by which multiple excitatory synapses on a neuron are activated simultaneously, leading to a cumulative effect on the neuron's membrane potential. This cumulative effect can result in depolarization that exceeds the threshold required to generate an action potential. Therefore, the statement "the firing of more than one excitatory synapse at the same time results in depolarization that is greater than threshold" best defines spatial summation.Rate this question:
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- 29.
Identify the example below that is NOT one of the "principals of sensory reception"
- A.
All receptors elicit action potentials in afferent nerve fibres
- B.
Action potentials from each type of sensor are slightly different due to differences in Na+ channel function
- C.
Each type of receptor is highly sensitive to 1 type of stimuli only
- D.
Afferent action potentials are interpreted differently based on where they terminate in the CNS
- E.
All of the above are correct
Correct Answer
B. Action potentials from each type of sensor are slightly different due to differences in Na+ channel functionExplanation
The correct answer is "Action potentials from each type of sensor are slightly different due to differences in Na+ channel function." This statement is not one of the "principals of sensory reception" because it refers to the differences in Na+ channel function, which is not a principle of sensory reception. The principles of sensory reception include all receptors eliciting action potentials in afferent nerve fibers, each type of receptor being highly sensitive to one type of stimuli only, and afferent action potentials being interpreted differently based on where they terminate in the CNS.Rate this question:
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- 30.
The muscle stretch reflex is initiated by a group of sensory nerves called the muscle spindle. The muscle spindle is wrapped around which type of muscle fibre?
- A.
Extrafusal Fibres
- B.
Primary Fibres
- C.
Intarfusal Fibres
- D.
Intermediate Fibres
- E.
None of the above
Correct Answer
C. Intarfusal FibresExplanation
The muscle stretch reflex is initiated by a group of sensory nerves called the muscle spindle. The muscle spindle is wrapped around intrafusal fibers.Rate this question:
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- 31.
The knee jerk reflex is a clinical test for proper function of which of the following reflex
- A.
Withdrawal reflex
- B.
Muscle Stretch Reflex
- C.
Golgi Tendon Reflex
Correct Answer
B. Muscle Stretch ReflexExplanation
The knee jerk reflex is a clinical test that assesses the function of the Muscle Stretch Reflex. This reflex is also known as the patellar reflex and is triggered when the patellar tendon is tapped, causing the quadriceps muscle to contract and extend the leg. This reflex is important for maintaining posture and balance, as well as protecting the body from potential harm. The withdrawal reflex is a different reflex that involves the removal of a body part from a harmful stimulus, while the Golgi Tendon Reflex is responsible for preventing excessive tension in muscles.Rate this question:
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- 32.
Once an afferent neuron enters the spinal column it travels towards the brain via
- A.
Grey matter
- B.
Dorsal Column
- C.
Central Canal
- D.
Ventral Horn
- E.
Corticospinal Tract
Correct Answer
B. Dorsal ColumnExplanation
Once an afferent neuron enters the spinal column, it travels towards the brain via the dorsal column. The dorsal column is a pathway in the spinal cord that carries sensory information from the body to the brain. It is located towards the back (dorsal) of the spinal cord and consists of two main tracts, the fasciculus gracilis and the fasciculus cuneatus. These tracts relay sensory information such as touch, pressure, and proprioception to the brain for processing and interpretation. Therefore, the correct answer is the dorsal column.Rate this question:
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- 33.
An Afferent action potential occurs ___ synapse(s) between the sensory receptor and its termination in the somatosensory area of the brain
- A.
1
- B.
2
- C.
3
- D.
4
- E.
5
Correct Answer
B. 2Explanation
An afferent action potential occurs at two synapses between the sensory receptor and its termination in the somatosensory area of the brain. This means that the sensory information travels through two synapses before reaching the somatosensory area. The first synapse occurs between the sensory receptor and the primary sensory neuron, while the second synapse occurs between the primary sensory neuron and the somatosensory area of the brain.Rate this question:
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- 34.
The ability of basketball players to adjust their shots in mid-air is a result of which of the following areas of the brain?
- A.
Limbic System
- B.
Motor Cortex
- C.
Cerebellum
- D.
Basal Ganglia
- E.
Brain Stem
Correct Answer
C. CerebellumExplanation
The cerebellum is responsible for coordinating voluntary movements and maintaining balance and posture. It receives information from the sensory systems, the spinal cord, and other parts of the brain, and then regulates and fine-tunes motor movements. Adjusting shots in mid-air requires precise control over motor movements, including adjusting the angle, speed, and force of the shot. Therefore, the ability of basketball players to adjust their shots in mid-air is likely a result of the cerebellum's role in motor coordination and control.Rate this question:
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- 35.
What would the rate of flow be for water through a hose given a pressure gradient of 200 mmHg and a conductance of 2 L/mmHg/min?
- A.
400 L/min
- B.
0.01 L/min
- C.
100 L/min
- D.
2 L/min
Correct Answer
A. 400 L/minExplanation
The rate of flow for water through a hose can be calculated using the formula: Flow rate = Pressure gradient / Conductance. In this case, the pressure gradient is given as 200 mmHg and the conductance is given as 2 L/mmHg/min. Plugging these values into the formula, we get: Flow rate = 200 mmHg / 2 L/mmHg/min = 100 L/min. Therefore, the correct answer is 100 L/min.Rate this question:
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- 36.
Identify the example below that represents an INCREASE in conductance
- A.
Placing an NFL lineman in a doorway and telling him to stop people from entering
- B.
A highway increasing lanes of traffic from 1 to 3
- C.
Closing the entry gates to a football game
- D.
The number of people trying to enter a building double from 250 to 500
Correct Answer
B. A highway increasing lanes of traffic from 1 to 3Explanation
Increasing the lanes of traffic from 1 to 3 on a highway represents an increase in conductance. Conductance refers to the ease with which a substance or flow can pass through a given medium. In this case, increasing the number of lanes on a highway allows for a greater flow of traffic, indicating an increase in conductance.Rate this question:
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- 37.
Which of the following is an example of feedback control (positive or negative)?
- A.
Increasing the release of a hormone as a result of high plasma levels of the same hormone
- B.
Decreasing the uptake of plasma glucose into skeletal muscle as a result of high muscle glucose content
- C.
Increasing the production of saliva as a result of stimulation of olfactory receptors (small receptors) in the nose
- D.
A and B
Correct Answer
D. A and BExplanation
The correct answer is A and B. These options both demonstrate negative feedback control. In option A, the release of a hormone is increased in response to high plasma levels of the same hormone, which helps to regulate and maintain hormone levels within a certain range. In option B, the uptake of plasma glucose into skeletal muscle is decreased in response to high muscle glucose content, which helps to prevent excessive glucose uptake and maintain glucose homeostasis. Both examples illustrate feedback mechanisms that work to counteract and regulate changes in the body.Rate this question:
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- 38.
Of the following examples, only ______ could be defined as exergonic
- A.
Metabolism producing ATP from ADP and an inorganic phosphate
- B.
A firecracker exploding in mid air
- C.
A tree using photosynthesis to produce glucose
- D.
None of the above are exergonic
Correct Answer
B. A firecracker exploding in mid airExplanation
An exergonic reaction is a chemical reaction that releases energy. In the given examples, only the firecracker exploding in mid-air can be defined as exergonic because it involves a rapid release of energy in the form of heat, light, and sound. Metabolism producing ATP from ADP and an inorganic phosphate is an endergonic reaction as it requires energy input. A tree using photosynthesis to produce glucose is also an endergonic reaction as it requires energy from sunlight. Therefore, the correct answer is the firecracker exploding in mid-air.Rate this question:
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- 39.
When ATP is broken down to ADP, how many inorganic phosphates are released from the molecule of ATP
- A.
1
- B.
2
- C.
3
Correct Answer
A. 1Explanation
When ATP is broken down to ADP, only one inorganic phosphate is released from the molecule of ATP. ATP (adenosine triphosphate) is a high-energy molecule that stores energy in its phosphate bonds. When one phosphate group is removed from ATP, it becomes ADP (adenosine diphosphate), and the released phosphate can be used for various cellular processes. Therefore, the correct answer is 1.Rate this question:
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- 40.
Which of the following is TRUE regarding enzyme function
- A.
Enzymes change chemical reactions from exergonic to endergonic
- B.
​​​​​​Enzymes speed the rate of a reaction by increasing the number of substrates
- C.
​​​​​​​Enzymes speed the rate of a reaction by increasing activation energy
- D.
​​​​​​​Enzymes speed the rate of a reaction by bringing substrates close to one another so that they are more likely to react
Correct Answer
D. ​​​​​​​Enzymes speed the rate of a reaction by bringing substrates close to one another so that they are more likely to reactExplanation
Enzymes speed up the rate of a reaction by bringing substrates close to one another so that they are more likely to react. This is known as the enzyme's catalytic function. By binding to the substrates, enzymes create an environment that is conducive to the chemical reaction, allowing it to occur more quickly. Enzymes do not change the thermodynamics of a reaction, so they do not convert exergonic reactions to endergonic ones. Additionally, enzymes do not increase the number of substrates or alter the activation energy of a reaction.Rate this question:
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- 41.
Which of the following is true regarding enzyme kinetics?
- A.
Increasing substrate concentration and decreasing enzyme concentration both increase the rate of reaction
- B.
Increasing substrate concentration and increasing enzyme concentration both decrease the rate of reaction
- C.
Decreasing substrate concentration and increasing enzyme concentration both increase the rate of reaction
- D.
None of the above are true
Correct Answer
D. None of the above are trueExplanation
The correct answer is "None of the above are true" because increasing substrate concentration typically increases the rate of reaction, while increasing enzyme concentration also increases the rate of reaction. Decreasing substrate concentration and increasing enzyme concentration may not always lead to an increase in the rate of reaction, as the reaction rate is dependent on the availability of both substrate and enzyme. Therefore, none of the statements provided in the options are true regarding enzyme kinetics.Rate this question:
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- 42.
Increasing the number of available enzymes in a chemical reaction increases the production of product from substrate as a result of which of the following
- A.
Decreasing the mass of product
- B.
Increasing P1
- C.
Increasing conductance
- D.
Increasing ∆ P
Correct Answer
C. Increasing conductanceExplanation
Increasing the number of available enzymes in a chemical reaction increases the production of product from substrate because enzymes act as catalysts, speeding up the reaction rate. By increasing the conductance, the movement of charged particles, such as ions, is facilitated, allowing for more efficient enzyme-substrate interactions. This leads to a higher rate of product formation. Therefore, increasing conductance is the most likely option to increase the production of product from substrate.Rate this question:
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- 43.
In which of the following types of transports is ATP breakdown directly and or indirectly involved
- A.
Primary active transport
- B.
Co-transport
- C.
Counter-transport
- D.
All of the above require the breakdown of ATP
Correct Answer
D. All of the above require the breakdown of ATPExplanation
All of the above types of transport, including primary active transport, co-transport, and counter-transport, require the breakdown of ATP. ATP is the main source of energy for cellular processes, including the movement of molecules across cell membranes. In primary active transport, ATP is directly involved in the transport process, providing the energy needed to move molecules against their concentration gradient. In co-transport and counter-transport, ATP is indirectly involved as it powers the ion pumps that establish and maintain the concentration gradients necessary for these transport mechanisms to occur.Rate this question:
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- 44.
Which of the following is NOT part of a gene
- A.
Repressor region
- B.
Promotor region
- C.
Coding region
- D.
All of the above are part of a gene
Correct Answer
A. Repressor regionExplanation
The repressor region is not part of a gene. Genes consist of three main regions: the promoter region, which initiates gene expression; the coding region, which contains the instructions for protein production; and the terminator region, which marks the end of the gene. The repressor region, on the other hand, is a DNA sequence that binds to a repressor protein, preventing gene expression by blocking the binding of RNA polymerase to the promoter region. Therefore, it is not considered part of the gene itself.Rate this question:
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- 45.
Which of the following represents the path a newly formed protein would take as it travels from a ribosome to the cell membrane?
- A.
Mitochondria --> endoplasmic reticulum --> membrane
- B.
Endoplasmic reticulum --> mitochondria --> vesicle --> membrane
- C.
Golgi apparatus --> endoplasmic reticulum --> membrane
- D.
Endoplasmic reticulum --> golgi apparatus --> vesicle --> membrane
Correct Answer
D. Endoplasmic reticulum --> golgi apparatus --> vesicle --> membraneExplanation
The correct answer is "Endoplasmic reticulum -> golgi apparatus -> vesicle -> membrane" because newly formed proteins are synthesized by ribosomes attached to the endoplasmic reticulum. From there, the proteins are transported to the Golgi apparatus, where they undergo modifications and packaging into vesicles. These vesicles then transport the proteins to the cell membrane for secretion or integration into the membrane.Rate this question:
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- 46.
If you were to increase the transcription of your mitochondrial genes, how would you expect this to affect your endurance exercise performance?
- A.
Your performance would get better
- B.
Your performance would get worse
- C.
Your performance would not change because this would not increase the rate of translation of these genes
Correct Answer
A. Your performance would get betterExplanation
Increasing the transcription of mitochondrial genes would lead to an increase in the production of mitochondrial proteins. These proteins are essential for energy production in the cells, particularly during endurance exercise. More mitochondrial proteins would enhance the capacity of the mitochondria to generate ATP, the energy currency of the cell. As a result, increasing the transcription of mitochondrial genes would improve the efficiency of energy production, leading to better endurance exercise performance.Rate this question:
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- 47.
Which of the following statements is TRUE about “leak” channels and their relationship to membrane potential?
- A.
A single leak channel will allow both Na+ and K+ to diffuse freely across cell membranes
- B.
Leak channels are the main reason that K+ contributes more to membrane potential than Na+
- C.
Leak channels allow x1000 more Na+ to diffuse than K+
- D.
Leak channels are composed of phospholipids
Correct Answer
B. Leak channels are the main reason that K+ contributes more to membrane potential than Na+Explanation
Leak channels are the main reason that K+ contributes more to membrane potential than Na+. This is because leak channels are selective for certain ions, and there are more leak channels for K+ than for Na+ in the cell membrane. As a result, K+ ions can diffuse out of the cell more easily through leak channels, leading to a higher concentration of K+ outside the cell and a more negative membrane potential. On the other hand, Na+ ions are less able to diffuse through leak channels, resulting in a lower concentration of Na+ inside the cell and a less negative membrane potential compared to K+.Rate this question:
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- 48.
What is the resting membrane potential of a neuron
- A.
+ 70 mV
- B.
- 70 mV
- C.
+ 30 mV
- D.
- 93 mV
Correct Answer
B. - 70 mVExplanation
The resting membrane potential of a neuron refers to the electrical charge difference across the cell membrane when the neuron is at rest. A negative value indicates that the inside of the neuron is more negatively charged compared to the outside. In this case, the correct answer of -70 mV suggests that the inside of the neuron is 70 millivolts more negative than the outside. This negative charge is maintained by the activity of ion channels and pumps in the neuron's membrane.Rate this question:
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- 49.
What would opening a Na+ channel located within the membrane of a resting neural cell would do to that neuron’s membrane potential?
- A.
Make it more positive
- B.
Make it more negative
- C.
Opening a Na+ channel would have no impact on membrane potential
Correct Answer
A. Make it more positiveExplanation
Opening a Na+ channel located within the membrane of a resting neural cell would make the neuron's membrane potential more positive. This is because Na+ ions have a positive charge, and when the channel opens, Na+ ions flow into the cell, increasing the overall positive charge inside the cell. This depolarizes the membrane potential, bringing it closer to the threshold for generating an action potential.Rate this question:
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- 50.
Which of the following is true regarding potassium (K+)?
- A.
Leak channels in the cell membrane are more permeable to sodium than potassium
- B.
During depolarization, potassium concentration is higher inside the cell than outside
- C.
The Na+/K+ pump brings 3 ions of Na+ into the cell for every K+ it expels out of the cell
- D.
The rest (-70 mV), voltage-gated potassium channels allow potassium to flow into the cell
Correct Answer
B. During depolarization, potassium concentration is higher inside the cell than outsideExplanation
During depolarization, potassium concentration is higher inside the cell than outside. This is because depolarization refers to the process of the cell becoming less negative and more positive. During depolarization, potassium channels open, allowing potassium ions to flow out of the cell, which increases the concentration of potassium inside the cell compared to outside. This movement of potassium ions helps to repolarize the cell and restore its resting membrane potential.Rate this question:
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Quiz Review Timeline +
Our quizzes are rigorously reviewed, monitored and continuously updated by our expert board to maintain accuracy, relevance, and timeliness.
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Current Version
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Mar 15, 2023Quiz Edited by
ProProfs Editorial Team -
Feb 03, 2020Quiz Created by
Lexie Ingoldsby
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