BIO 361 Biology Practice Exam: Trivia Quiz

27 Questions | Total Attempts: 606

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BIO 361 Biology Practice Exam: Trivia Quiz

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Questions and Answers
  • 1. 
    Why does the rate of glucose transport via Glut-1 only increase up to a certain level, but then stabilize even when external glucose concentration increases?
    • A. 

      Glut-1 transporters become exhausted and stop working.

    • B. 

      All available transporters are working at their maximal rate.

    • C. 

      The driving force for glucose movement has levelled off.

  • 2. 
    How could a cell increase its maximum rate of glucose transport?
    • A. 

      Reduce the total number of Glut-1 transporters.

    • B. 

      Reduce internal glucose concentration to increase the driving force for glucose movement.

    • C. 

      Increase internal glucose concentration to increase the driving force for glucose movement.

    • D. 

      Increase the total number of Glut-1 transporters.

  • 3. 
    If you measured desaturase enzyme activity in a goldfish living at 10 degrees Celsius and compared it to desaturase enzyme activity in a goldfish living at 30 degrees Celsius you would expect:
    • A. 

      Desaturase activity to be similar

    • B. 

      Desaturase activity to be higher in the warm fish

    • C. 

      Desaturase activity to be higher in the cold fish

  • 4. 
    Which of the following changes will result in an increase in membrane fluidity?
    • A. 

      Increasing the temperature

    • B. 

      Increasing membrane unsaturation

    • C. 

      Decreasing membrane unsaturation

    • D. 

      Both a and b

    • E. 

      Both a and c

  • 5. 
    Which of the following changes will result in an increase in membrane fluidity?
    • A. 

      Increasing the temperature

    • B. 

      Increasing membrane unsaturation

    • C. 

      Decreasing membrane unsaturation

    • D. 

      Both a and b

    • E. 

      Both a and c

  • 6. 
    When comparing an Antarctic fish (body temperature ~1 degree Celsius) and a bird (body temperature ~41 degrees Celsius) you would expect:
    • A. 

      The Antarctic fish to have more unsaturated membrane fatty acids

    • B. 

      The bird to have more unsaturated membrane fatty acids

    • C. 

      It is impossible to predict which one would have more unsaturated membrane fatty acids.

  • 7. 
    If you measured the membrane fluidity of two artificial bilayers, one containing cholesterol, and one lacking cholesterol:
    • A. 

      The relative fluidity of the bilayers would depend on the temperature of measurement.

    • B. 

      The cholesterol containing bilayer would have higher fluidity.

    • C. 

      The cholesterol containing bilayer would have lower fluidity.

  • 8. 
    ___________ is the ability to do work.
    • A. 

      Force

    • B. 

      Energy

    • C. 

      Potential

    • D. 

      Power

  • 9. 
    Glucose exhibits a(n) _______________ gradient across the cell membrane
    • A. 

      Electrochemical

    • B. 

      Steep

    • C. 

      Chemical

    • D. 

      Electrical

  • 10. 
    As a general rule, lipid-soluble molecules cross membranes by ______________.
    • A. 

      Active transport

    • B. 

      Passive diffusion

    • C. 

      Facilitated diffusion

    • D. 

      All of the above

  • 11. 
    A(n) _______________ facilitates diffusion by binding to its substrate and undergoing a conformational change to transport the substrate across the membrane.
    • A. 

      Permease

    • B. 

      Ion channel

    • C. 

      Porin

    • D. 

      Voltage-gated channel

  • 12. 
    Which of the following statements is true concerning secondary active transporters?
    • A. 

      An exchanger/antiporter will always be electroneutral

    • B. 

      Electrogenic carriers generate a charge difference across the membrane

    • C. 

      A symporter can bind only one particle

    • D. 

      The direction in which charged particules are transported across the the membrane does not affect the electrical gradient

  • 13. 
    The equilibrium potential and the reversal potential for a cell are interchangeable terms, assuming only one ion is being considered.
    • A. 

      True

    • B. 

      False

  • 14. 
    The Goldman equation is used to calculate the _____________ of a cell.
    • A. 

      Action potential

    • B. 

      Resting membrane potential

    • C. 

      Reversal potential

    • D. 

      All of the above

  • 15. 
    • A. 

      The membrane is more permeable to Na+ than to any other ion

    • B. 

      The Na+/K+ pump is electroneutral

    • C. 

      The membrane is more permeable to K+ than to any other ion

    • D. 

      The interior of the cell contains a much higher concentration of Cl-

  • 16. 
    Compared to the outside of the cell membrane, the inside of the resting cell membrane is typically:
    • A. 

      Electrically neutral

    • B. 

      Extremely variable

    • C. 

      Negatively charged

    • D. 

      Positively charged

    • E. 

      Positively charged whenever the sodium pump is active.

  • 17. 
    Calculate the equilibrium potential for Na+ when the intracellular concentration of Na+ is 15mM and the extracellular concentration of Na+ is 145 mM.  The temperature is 37C (or 310K).  Note the Faraday's constant is 23,062 cal/V. mol, and the gas constant is 1.9872 cal/K. mol
    • A. 

      +60.6mV

    • B. 

      +60.6V

    • C. 

      0.0072V

    • D. 

      -60.6V

    • E. 

      -6-.6mV

  • 18. 
    Which of the following would make the membrane potential of a neuron less negative than its resting potential?
    • A. 

      Depolarization

    • B. 

      Hyperpolarization

    • C. 

      Repolarization

    • D. 

      Positively charged ions moving out of the cell

    • E. 

      Negatively charged ions moving into the cell

  • 19. 
    Several molecules of neurotransmitter arrive at the cell membrane of a vertebrae motor neuron dendrite and bind to several of the ligand-gated K+ channels there, stimulating them to open.  What will happen next?
    • A. 

      No graded potential will be generated because the cell membrane will hyperpolarize.

    • B. 

      K+ ions will leave the cell, hyperpolarizing the cell membrane.

    • C. 

      An excitatory graded potential will be generated.

    • D. 

      An action potential will be generated.

    • E. 

      K+ ions will enter the cell, depolarizing the cell membrane.

  • 20. 
    Which of the following will happen when a subthreshold excitatory stimulus reaches the axon hillock?
    • A. 

      All of the voltage-gated Na+ channel will open, depolarizing the cell membrane.

    • B. 

      No voltage gated sodium channels will open and the greater potential will continue to travel into the axon, decreasing in magnitude until it dies away completely

    • C. 

      Only some of the voltage gated sodium channels will open, so it will only generate a small action potential

    • D. 

      Only some of the voltage gated sodium channels will open, so it will only generate a graded potential

    • E. 

      An action potential will be generated

  • 21. 
    At the axon hillock, which of the following is most likely to trigger an action potential?
    • A. 

      One excitatory subthreshold graded potential that arrives at exactly the same time as a second subthreshold excitatory graded potential.

    • B. 

      One excitatory threshold graded potential that arrives at exactly the same time as one inhibitory graded potential.

    • C. 

      One excitatory suprathreshold graded potential that arrives just one millisecond after two inhibitory graded potential

    • D. 

      One excitatory subthreshold graded potential that arrives several seconds after another subthreshold excitatory graded potential.

    • E. 

      One excitatory subthreshold graded potential.

  • 22. 
    The axon hillock is incapable of generating an action potential while...
    • A. 

      Its cell membrane is hyperpolarized

    • B. 

      It is in the after hyperpolarization phase of an action potential

    • C. 

      It is in the relative refractory period

    • D. 

      It is in the absolute refractory period

    • E. 

      It is stimulated by a suprathreshold graded potential

  • 23. 
    In a squid giant axon, the length of the relative refractory period is mainly determined by ...
    • A. 

      The binding of neurotransmitters to the voltage gated sodium channels

    • B. 

      The magnitude of the graded potential that stimulated the action potential.

    • C. 

      The length of time that the voltage gated potassium channel remain open

    • D. 

      The timing of the activation gate of the voltage gated sodium channels

    • E. 

      The timing of the inactivation gate of the voltage gated sodium channels

  • 24. 
    In a squid giant axon, closing of the inactivation gates of the voltage gated Na+ channel ends the ...
    • A. 

      Depolarization phase of an action potential

    • B. 

      Repolarization phase of an action potential

    • C. 

      Afterhyperpolarization phase of an action potential

    • D. 

      Absolute refractory period

    • E. 

      Relative refractory period

  • 25. 
    Why can action potentials be transmitted over long distances while graded potentials can only be transmitted over relatively short distances?
    • A. 

      Action potentials are self-propagating while graded potentials are not

    • B. 

      Charged ions leak across the membrane when graded potentials are conducted in a neuron, but not when action potentials are conducted

    • C. 

      Action potentials travel only by ions moving through ion channels while graded potentials travel by electronic current spread

    • D. 

      Action potentials travel by electrotonic current spread while graded potentials travel only by ions moving through ion channels

    • E. 

      Action potentials are always larger in magnitude than graded potentials so they can further without dying away