Bil 265, Physiology, Spring 09 - First Examination - Form 1

1. Suppose that a cell membrane is only permeable to Sodium (+1). At 37 degrees C, what is the membrane potential (inside the cell) if the concentration of Sodium inside the cell is 10mM and the concentration of Sodium outside the cell is 0.001mM

1) -124mV
2) -186mV
3) +186mV
4) +248mV
5) -248mV

Correct Answer is: 5


2. Suppose that the only two ions permeable across a cell membrane are potassium (+1) and lithium (+1). You discover that these two ions are equally permeable across the membrane. Suppose potassium concentrations are: 100 mM inside the cell and 10 mM outside the cell. According to Donnan equilibrium, what concentration of lithium must you put outside the cell in order to make the concentration of lithium inside the cell equal to 50 mM?

1) 0.05 mM.
2) 0.5 mM.
3) 5 mM.
4) 50 mM.
5) 500mM.

Correct Answer is: 3


3. What particular adaptation does the icefish use to allow it to live in Antarctic waters?

1) It has an almost spherical shape, thus reducing surface area to volume ratio and preventing heat loss.
2) The icefish has modified eye muscles that act as heaters.
3) The icefish has one of the highest metabolic rates, per gm of body mass, of any animal on Earth.
4) The blood contains glycoproteins, with a high amount of the amino acid alanine.

Correct Answer is: 4


4. Long-lived organisms, who have a long time to maturity and produce few offspring for each pair of parents generally are:

1) M-selected
2) r-selected
3) K-selected
4) non-Darwinian in evolutionary strategy

Correct Answer is: 3


5. The "flyball governor" is or was:

1) the former governor of a certain midwest state.
2) a model for the rotation of sodium channels in a cell membrane
3) a mechanical mechanism that uses negative feedback.
4) a part of the hypothalamus

Correct Answer is: 3


6. What does a higher Michaelis constant, Km, indicate?

1) Km describes the difference in metabolic rate with a ten degree increase in temperature. A higher Km indicates an increased value for this difference in metabolic rate.
2) A higher substrate concentration is required for an enzyme to give the same rate of product production.
3) increased fluidity (increased ease of lateral movement) of a cell membrane.
4) decreased fluidity (decreased ease of lateral movement) of a cell membrane

Correct Answer is: 2


7. A steady state condition, also known in physiology as homeostasis:

1) is the same as an equilibrium state
2) gives a maximum rate of entropy production.
3) gives a maximum rate of enthalpy production
4) gives a minimum rate of entropy production.
5) gives a minimum rate of enthalpy production

Correct Answer is: 4


8. Suppose that we start with a cube-shaped animal with equal dimensions of length, width, and depth. Now, we imagine another animal which has the same length and width but twice the depth. As a result, the volume (V), of the larger, rectangle-shaped, animal becomes:

1) twice as large as that for the smaller animal.
2) 4 times as large as that for the smaller animal.
3) 6 times as large as that for the smaller animal.
4) 8 times as large as that for the smaller animal.

Correct Answer is: 1


9. Suppose that we start with a cube-shaped animal with equal dimensions of length, width, and depth. Now, we imagine another animal which has the same length and width but twice the depth. As a result, the ratio, S/V, of the larger, rectangle-shaped, animal's surface area (S) to its volume (V) becomes:

1) 1/2 as large as that for the smaller animal.
2) 1/4 as large as that for the smaller animal.
3) 2/3 as large as that for the smaller animal.
4) 5/6 as large as that for the smaller animal.
5) 5/8 as large as that for the smaller animal.

Correct Answer is: 4


10. Suppose that we start with a cube-shaped animal with equal dimensions of length, width, and depth. Now, we imagine another animal which has the same length and width but twice the depth. Using terminology discussed in class, which best describes the relationship between shapes of these two animals?

1) morphometric
2) allometric
3) fractal
4) isotonic
5) isometric

Correct Answer is: 2


11. True or False: K-selected animals would likely have fewer physiological processes in homeostasis than would r-selected animals.

1) True
2) False

Correct Answer is: 2


12. Which of the following is the name that best describes individual molecules of alanine, glycine?

1) sugar alcohol
2) amino acid
3) lipid
4) sugar

Correct Answer is: 2


13. Which of the following is the name that best describes individual molecules of glycerol, sorbitol?

1) sugar alcohol
2) amino acid
3) lipid
4) protein
5) steroid

Correct Answer is: 1


14. Which of the following best describes the "rete mirabile"?

1) modified eye muscles in Swordfish
2) prevents Icefish blood from freezing
3) a region of the bird and mammal brains that senses temperature
4) a heat storage organ in some large fish

Correct Answer is: 4


15. Assume that the proportions of different animals scale isometrically with length of the animal. If we plot the log of each animal's volume against the log of the animal's surface area, we obtain a straight line. What is the slope of that straight line?

1) 0.5
2) 0.67
3) 1.5
4) 2.
5) 3.

Correct Answer is: 3


16. Which of the following is most accurate concerning the drug "Celebrex"?

1) Is used to treat rheumatoid arthritis.
2) Decreases thyroxine production in those people with an overactive thyroid.
3) Inhibits production of the hormone ADH by the posterior pituitary.
4) Used to keep blood thin when the patient is cooled during some types of surgery.

Correct Answer is: 1


17. A cell membrane has equal conductance to sodium ions as to calcium ions, and no conductance to any other ions. The sodium Nernst potential is +60 mV and the calcium Nernst potential is -60 mV. What is the actual membrane potential (inside the cell)?

1) zero
2) +10 mV
3) +20 mV
4) +30 mV
5) +40 mV

Correct Answer is: 1


18. As a physician, you are visited by a drug company representative. She tells you that she has a drug, called Verapamil, that will lower blood pressure in your patients. Which of the following is most accurate concerning her claims:

1) She is very confused. Verapamil is a prescription medication used in emergencies to reduce very high fever. The sales representative much have been reading the wrong data sheet.
2) She is absolutely correct. A sufficient dose of Verapamil will block sodium channels on nerve cells, thus preventing transmission of action potentials. Death will follow. Of course, one consequence of death is that blood pressure will have been reduced to zero.
3) She is absolutely correct. Verapamil is commonly prescribed to reduce blood pressure. It blocks calcium channels and thus reduces the stimulation of muscle tissue, including that of the heart.
4) She is very confused. Verapamil is a pyrogen produced by bacteria. Pyrogens induce fever but don't decrease blood pressure.

Correct Answer is: 3


19. As a physician, you are visited by a drug company representative. She tells you that she has a drug, called Tetrodotoxin, that will lower blood pressure in your patients. Which of the following is most accurate concerning her claims:

1) She is very confused. Tetrodotoxin is a prescription medication used in emergencies to reduce very high fever. The sales representative much have been reading the wrong data sheet.
2) She is absolutely correct. A sufficient dose of Tetrodotoxin will block sodium channels on nerve cells, thus preventing transmission of action potentials. Death will follow. Of course, one consequence of death is that blood pressure will have been reduced to zero.
3) She is absolutely correct. Tetrodotoxin is commonly prescribed to reduce blood pressure. It blocks calcium channels and thus reduces the stimulation of muscle tissue, including that of the heart.
4) She is very confused. Tetrodotoxin is a pyrogen produced by bacteria. Pyrogens induce fever but don't decrease blood pressure.

Correct Answer is: 2


20. Which of the following best describes threonin (also spelled threonine)?

1) An endogenous pyrogen
2) A sugar alcohol.
3) An antifreeze glycoprotein.
4) A glycoprotein.
5) An amino acid.

Correct Answer is: 5


21. The "waterproof frogs" are examples of:

1) orientation of the body to avoid overheating by sunlight.
2) water conservation in a desert animal.
3) an adaptation to permit supercooling.
4) poisonous frogs that produce an inhibitor of synaptic transmission.
5) cooling of the animal by evaporation.

Correct Answer is: 5


22. What is the role of uncoupling proteins in the mitochondria of animals?

1) These proteins are enzymes that make Cyclooxygenase.
2) These proteins are endogenous pyrogens.
3) They are comprised mainly of alanine.
4) They allow heat to be generated without making any ATP.

Correct Answer is: 4


23. True or False: Most birds can regulate their body temperature by endothermy but most fish cannot.

1) True
2) False

Correct Answer is: 1


24. TRUE OR FALSE: The action potential is an example of electrotonic spread of potential change?

1) TRUE
2) FALSE

Correct Answer is: 2


25. Suppose that a cell membrane is only permeable to Iron (+3). At 37 degrees C, what is the membrane potential (inside the cell) if the concentration of Iron outside the cell is 50mM and the concentration of Iron inside the cell is 0.00005mM

1) +103.3 mV
2) -103.3 mV
3) +124.0 mV
4) -124.0 mV
5) +144.7 mV

Correct Answer is: 3


26. What would the osmotic consequence be if the Na+/K+ ATPase pump, as found in most vertebrate nerve or muscle cells, stopped working?

1) The cell would swell and perhaps burst.
2) The cell would shrink.
3) The cell would neither shrink nor swell.

Correct Answer is: 1


27. For a typical nerve or muscle cell, which of the following best describes the concentration of Potassium outside the cell in blood plasma?

1) .0001 Molar
2) .01 Molar
3) 10 Molar
4) 100 Molar

Correct Answer is: 2


28. Which molecule is produced by cells in the human body and acts directly on neurons in the hypothalamus, resetting the firing rate of nerve impulses?

1) Trehalose
2) Interleukins
3) heat shock proteins
4) Prostaglandins.
5) Cyclooxygenase

Correct Answer is: 4


29. True or False: The Goldman equation can predict the membrane potential if we know the permeabilities for all ions, the concentrations of all ions, and all ions are divalent (+/- 2 charge).

1) True
2) False

Correct Answer is: 2


30. From the start of the action potential on vertebrate nerve or muscle cells to the end of the action potential, what happens to the conductance of membrane channel proteins to chloride?

1) The conductance of the membrane to chloride remains constant.
2) Rises to a peak, then falls back to resting levels (those levels before and after the action potential) until the next action potential passes.
3) Rises to a peak, then falls back to below resting levels, and finally rises back to resting levels.
4) Falls to values lower than at rest and then returns to resting values. The conductance is never higher than the resting level.

Correct Answer is: 1


31. From the start of the action potential on vertebrate nerve or muscle cells to the end of the action potential, what happens to the conductance of conductance of membrane channel proteins to sodium?

1) The conductance of the membrane to sodium remains constant.
2) Rises to a peak, then falls back to resting levels (those levels before and after the action potential) until the next action potential passes.
3) Rises to a peak, then falls back to below resting levels, and finally rises back to resting levels.
4) Falls to values lower than at rest and then returns to resting values. The conductance is never higher than the resting level.

Correct Answer is: 2


32. For a resting vertebrate skeletal (voluntary) muscle cell, with no action potentials, what is the ratio (approximately), of the conductance of the membrane to sodium divided by conductance of the membrane to chloride?

1) 1
2) 100
3) 1000
4) 1/1000
5) 1/100

Correct Answer is: 5


33. True or False: Supercooling requires molecules that promote freezing point depression.

1) True
2) False

Correct Answer is: 2


34. "Homeoviscous membrane adaptation" is best described as:

1) More myelin is produced.
2) Protein channels become more conductive to Sodium ions when a nerve cell membrane is depolarized.
3) Glycoproteins are produced in the cell interior.
4) Membrane lipids are replaced by those with a different amount of saturation and/or the percentage of cholesterol in the membrane is changed.

Correct Answer is: 4


35. As the result of one action potential, how much does the sodium concentration inside a typical nerve axon increase or decrease? (As always, choose the best answer.)

1) increases by 0.0001%
2) increases by 1%
3) increases by 10%
4) decreases by 10%
5) increases by 100%

Correct Answer is: 1


36. Which of the glands or organs is the primary detector of core body temperature in mammals?

1) Pituitary gland
2) Adrenal glands.
3) Thyroid gland
4) Pancreas
5) Hypothalamus

Correct Answer is: 5


37. The sodium Nernst potential is +60 mV and the potassium Nernst potential is -60mv. The sodium conductance is 1/4 of the total conductance of the membrane to sodium and potassium. No other ions are involved. What is the membrane potential?

1) zero.
2) -30 mV.
3) +30 mV.
4) -60 mV.
5) +60 mV.

Correct Answer is: 2


38. Which of the following are characteristics of a squid or lobster giant axon?

1) Either has a very small diameter compared with human spinal neurons.
2) Squid or lobster giant axons, unlike most other types of nerve cells, don't have action potentials. Information is transmitted by slow, graded electrical potentials, not action potentials.
3) Concentrations of sodium inside the axon are very high, 100mM or more, compared with most other cells.
4) Has no nodes of Ranvier.

Correct Answer is: 4


39. Which of the following is a correct statement of Ohm's law, the relationship between voltage V across a resistive channel and the resulting current I? (R is resistance and g is conductance.)

1) I = V/g
2) g = 1/R
3) I = V R
4) I = g V
5) Two or more of the above answers are equally correct.

Correct Answer is: 4


40. Which of the following organs or glands produces Thyroid Releasing Hormone (TRH)?

1) Thyroid gland
2) Adrenal gland
3) Pituitary gland
4) Kidney
5) Hypothalamus

Correct Answer is: 5