2010 Exam

Question 1

1. The bird and the bat wing shown opposite have bone structures that have a common origin (e.g. the bones labelled A and B in the diagram). These structures are _____________ .

Answer 1

a. homologous in the bird and bat

Question 2

3. Which ONE of the following statements is CORRECT?
   a. Total body water is composed of interstitial fluid and extracellular fluid
   b. The two extracellular fluid compartments of the body are interstitial fluid and plasma
   c. Total body water is defined as all the fluid within the plasma membrane
   d. All body cells contain intracellular fluid, except for red blood cells
   e. Most body cells are in direct contact with the external environment

Answer 2

b. The two extracellular fluid compartments of the body are interstitial fluid and plasma

Question 3

4. In a mammalian cell, which of the following solutes is at higher concentration in the intracellular fluid than in the extracellular fluid?
   a. Sodium (Na+) ions
   b. Potassium (K+) ions
   c. Chloride (Cl-) ions
   d. Bicarbonate (HCO3-) ions
   e. Calcium (Ca2+) ions

Answer 3

b. Potassium (K+) ions

Question 4

5. Which of the following is NOT a characteristic of plasma membrane transport proteins?
   a. Competition
   b. Selectivity
   c. Saturation
   d. Higher rates of transport than ion channels
   e. They can move large molecules across the plasma membrane

Answer 4

d. Higher rates of transport than ion channels

Question 5

What best explains how ligand-gated channels can be opened or closed?

Answer 5

b. They open/close in response to the presence of specific molecules.

Question 6

8. Homeostasis is defined as _________________

Answer 6

b. the maintenance of constancy in the internal environment

Question 7

why does adrenalin has varying effects upon different tissues?

Answer 7

a. Due to the presence of different receptors

Question 8

10. Four organ systems exchange material between external and internal environments. Which of the following does NOT conform to this description?
    a. Endocrine system
    b. Gastrointestinal system
    c. Reproductive system
    d. Respiratory system
    e. Urinary system

Answer 8

a. Endocrine system

Question 9

11. The 200+ types of cells in the vertebrate body are divided into four general categories (tissue types). Which of the following is NOT one of these tissue types?
    a. Connective tissue
    b. Epithelium
    c. Muscle
    d. Nervous tissue
    e. Integument

Answer 9

e. Integument

Question 10

What is the BEST definition of tissues?

Answer 10

b. Collections of cells performing related functions

Question 11

13. Glial cells are ___________

Answer 11

a. Cells that function in metabolic support of neurons and myelin production

Question 12

15. Which ONE of the following statements is CORRECT?
    a. Coronary arteries are required to provide blood supply to spongy myocardium.
    b. Crocodile hearts have two aortas, allowing blood to be shunted towards the lungs during diving.
    c. All endothermic homeotherms have evolved 4-chambered hearts.
    d. Amphibians have two ventricles and a single atrium.
    e. Fish (e.g. tuna) have single chambered hearts.

Answer 12

c. All endothermic homeotherms have evolved 4-chambered hearts.

Question 13

16. Which one of the following anatomical structures is NOT part of the lower respiratory tract?
    a. Trachea
    b. Alveoli
    c. Bronchi
    d. Pharynx
    e. Bronchioles

Answer 13

d. Pharynx

Question 14

17. Which of the following factors may cause bronchoconstriction?
    a. Increased lung compliance.
    b. Sympathetic nervous system.
    c. Histamine release.
    d. Exercise.
    e. Restrictive lung disease.

Answer 14

c. Histamine release.

Question 15

18. Which of the following is characteristic of a restrictive lung disease?
    a. Increased resistance.
    b. Increased compliance causing difficulty in lung expansion.
    c. Difficulty expiring, resulting in lung over-inflation.
    d. Increased total lung capacity.
    e. Decreased compliance causing difficulty in lung expansion.

Answer 15

e. Decreased compliance causing difficulty in lung expansion.

Question 16

19. Which cells are responsible for producing surfactant?

Answer 16

c. Type II alveolar cells

Question 17

What muscles involved in ACTIVE EXPIRATION in mammals?

Answer 17

e. Both the abdominal and internal intercostal muscles

Question 18

21. Which of the following is NOT a function of surfactant?
    a. Decreases cohesive forces between water molecules.
    b. Decreases work of breathing
    c. Reduces surface tension
    d. Prevents alveoli from collapse
    e. Decreases compliance

Answer 18

e. Decreases compliance

Question 19

22. A reduction, below normal, in the number or volume of red blood cells is called ___________ .

Answer 19

b. Anaemia

Question 20

24. Core body temperature is regulated only a few degrees (°C) below the point at which thermal death occurs (e.g. about 42-45°C in man). Explain why this phenomenon is likely to have evolved in vertebrates?

Answer 20

d. Physiological function is linked to the rate of biochemical processes, and therefore performance is enhanced at the higher temperatures

Question 21

25. Which of the following vertebrates does NOT represent an example of temporal heterothermy?
    a. A hummingbird entering torpor.
    b. A camel absorbing heat during the day (high Ta), dissipating the heat at night (low Ta).
    c. An antelope ground squirrel making brief trips out of its burrow in order to feed.
    d. An emperor penguin constricting blood flow to its legs when standing on ice, thereby reducing the temperature of its feet.
    e. A squirrel undergoing hibernation.

Answer 21

d. An emperor penguin constricting blood flow to its legs when standing on ice, thereby reducing the temperature of its feet.

Question 22

26. Select the best option given below to describe the process of Selective Brain Cooling.
    a. Certain species have a greater number of sweat glands over their scalp, in order to preferentially keep their brains cool.
    b. Blood leaving the nasal regions (where evaporative cooling takes place) cools arterial blood before it reaches the brain via a countercurrent exchange mechanism.
    c. Animals in cold environments (e.g. in Antarctic) have less insulation over their heads, in order to keep the Tbrain lower than the core temperature by increasing conductance of heat.
    d. A process valuable in reducing evaporative water loss in hot environments.
    e. Both b. and d.

Answer 22

e. Both b. and d.

Question 23

29. Which ONE of the following statements about resting membrane potential (RMP) is CORRECT?
    a. At RMP, K+ flows into the cell down its concentration gradient
    b. At RMP, Na+ is at electrochemical equilibrium
    c. At RMP, both K+ and Na+ flow into the cell down their electrical gradients
    d. At RMP, the membrane permeability to Na+ is the same as the membrane permeability to K+
    e. At RMP, the Na+/K+ ATPase pump maintains stable fluid composition by pumping Na+ into the cell and K+ out of the cell

Answer 23

c. At RMP, both K+ and Na+ flow into the cell down their electrical gradients

Question 24

30. Which ONE of the following statements is CORRECT?
    a. At equilibrium potential, the net influx of all ions in a cell down their chemical gradient is equal to the net efflux of those ions down their electrical gradient
    b. Membrane potential is the difference in charge between the inside and the outside of a cell, measured in millivolts.
    c. An anion carries a positive charge
    d. Only excitable cells have a resting membrane potential
    e. Current flow across the cell membrane is entirely determined by the intracellular and extracellular concentrations of different ions

Answer 24

b. Membrane potential is the difference in charge between the inside and the outside of a cell, measured in millivolts.

Question 25

31. Consider a typical mammalian neuron sitting at resting membrane potential. Which ONE of the following statements is CORRECT? a. Calcium influx will hyperpolarise the membrane potential b. Chloride influx will hyperpolarise the membrane potential c. Sodium influx will repolarise the membrane potential d. Potassium efflux will depolarise the membrane potential e. Influx of both calcium and chloride will hyperpolarise the membrane potential

Answer 25

b. Chloride influx will hyperpolarise the membrane potential

Question 26

32. Which ONE of the following statements about action potentials is CORRECT? a. Threshold is the membrane potential at which regenerative opening of voltage-gated sodium channels occurs b. Action potentials only involve active current flow c. The repolarisation phase is associated with potassium influx d. A stronger stimulus will produce a larger amplitude action potential e. The depolarisation phase is caused by opening of the inactivation gate on voltage-gated sodium channels

Answer 26

a. Threshold is the membrane potential at which regenerative opening of voltage-gated sodium channels occurs

Question 27

34. Consider a cell with a potassium equilibrium potential of –90 mV and a sodium equilibrium potential of +30 mV. Which ONE of the following statements is CORRECT about the movement of ions across the cell membrane? a. At a membrane potential of –70 mV there will be net potassium movement out of the cell b. At a membrane potential of –10 mV there will be net movement of sodium out of the cell c. At a membrane potential of –90 mV there will be no net movement of either sodium or potassium ions d. At a membrane potential of –30 mV there will be no net movement of either sodium or potassium ions e. At a membrane potential of +30 mV, sodium influx will be exactly balanced by potassium efflux

Answer 27

a. At a membrane potential of –70 mV there will be net potassium movement out of the cell

Question 28

36. What is another name for a receptor potential produced at sensory receptors?

Answer 28

a. Generator potential

Question 29

37. Which ONE of the following skin receptors is matched to its correct function? a. Merkel’s disks detect movement of hairs in the skin b. Ruffini’s corpuscles detect light pressure and high frequency vibration c. Meissner’s corpuscles detect touch and low frequency vibration d. Pacinian corpuscles detect heavy sustained pressure e. Nociceptors detect gentle mechanical stimuli

Answer 29

c. Meissner’s corpuscles detect touch and low frequency vibration

Question 30

38. When we enter a dark room after being in bright sunlight, which ONE of the following needs to occur before we can see well? a. Retinal and opsin molecules within the rods must bleach b. Retinal and opsin molecules within the rod must dissociate c. Retinal and opsin molecules within the cones must dissociate d. Retinal and opsin molecules within the rods must associate e. Retinal and opsin molecules within the cones must associate

Answer 30

d. Retinal and opsin molecules within the rods must associate

Question 31

39. The transduction of sound waves into neural impulses occurs in?

Answer 31

b. The organ of Corti

Question 32

40. The saccule detects movement in which directions?

Answer 32

e. Linear acceleration up or down

Question 33

41. Whether the hair cells in the semicircular canals are depolarised or hyperpolarised depends on which ONE of the following? a. The extent to which the stereocilia are bent b. The speed at which the stereocilia are bent c. The speed at which the head rotates d. The speed with which sodium ions enter the hair cells from the endolymph e. The direction toward which the stereocilia are bent relative to the kinocilium

Answer 33

e. The direction toward which the stereocilia are bent relative to the kinocilium

Question 34

43. Which of the following vertebrates are referred to as ‘osmo-conformers’? a. Sharks and rays. b. Marine teleosts. c. Freshwater teleosts. d. Mammals. e. All of the above.

Answer 34

a. Sharks and rays.

Question 35

45. Which of the following statements is FALSE regarding nitrogenous waste excretion? a. Water is needed for the storage and excretion of urea and therefore there is a minimum obligatory water loss associated with this form of nitrogen excretion. b. Urea is less toxic than ammonia, requiring ten times less water for storage and excretion at non-toxic concentrations. c. Synthesis of uric acid requires more energy than urea synthesis. d. Uric acid is very toxic and requires a quantity of H2O to dilute it to a non-toxic concentration. e. When amino acids are oxidised or converted to other kinds of molecules, the amino (NH2) group must be removed.

Answer 35

d. Uric acid is very toxic and requires a quantity of H2O to dilute it to a non-toxic concentration.

Question 36

49. The major site of storage of glycogen is the ___________.

Answer 36

a. liver

Question 37

50. The largest metabolic reserves for the average adult are stored as ___________.

Answer 37

d. triglycerides.

Question 38

51. The quality of food influences the time required for its digestion as well as the amount of energy eventually released. Choose the answer below that best describes the general features of ‘high quality food’: a. Animals expend a minimal amount of energy to capture and eat the food, it has a higher rate of digestion, and produces more energy. b. Animals expend a maximal energy to capture and eat the food, it has a higher rate of digestion, and produces more energy. c. Animals expend a minimal amount of energy to capture and eat the food, it has a slower rate of digestion, and produces more energy. d. Animals expend a minimal amount of energy to capture and eat the food, it has a slower rate of digestion, and produces less energy. e. Animals expend a maximal amount of energy to capture and eat the food, it has a slower rate of digestion, and produces less energy.

Answer 38

a. Animals expend a minimal amount of energy to capture and eat the food, it has a higher rate of digestion, and produces more energy.

Question 39

52. During the post-absorptive state, blood levels of insulin________, whereas blood levels of _______ Increase.

Answer 39

Decrease Glucagon

Question 40

53. Any excess glucose in the liver that is not required for energy and not stored as glycogen will ___________________ .

Answer 40

a. be converted into fatty acids

Question 41

54. The uptake of nutrients across the epithelial cells of the gastrointestinal tract into the bloodstream is called ________ .

Answer 41

d. absorption