125 terms

BIOL1040 - Clicker and MB Questions

STUDY
PLAY
Which of the following is NOT true about membrane phospholipids?
A. They are the main component of cell membranes.
B. They are amphipathic.
C. They are mobile.
D. They mediate movement of ions across membranes.
E. They can be saturated or non‐saturated.
D.
Which of the following amino acids would most likely be present in the transmembrane domain of an integral membrane protein?
A. A charged amino acid like lysine.
B. A polar amino acid like serine.
C. A special amino acid like glycine or proline.
D. A hydrophobic amino acid like valine.
E. Any of the above, with no preference.
D.
Which of the following molecules will move most quickly across a lipid bilayer membrane by simple diffusion?
A. K⁺.
B. CO₂.
C. Fructose.
D. HCO³⁻.
E. H₂O.
B.
Which statement about membranes is CORRECT?
A. Unsaturated phospholipids cause increased viscosity of the membrane.
B. Saturated phospholipids result in reduced membrane fluidity.
C. At body temperature, cholesterol increases the fluidity of membranes.
D. Unsaturated phospholipids are less kinked than saturated lipids.
E. Because of its "ordered " structure, cholesterol always decreases the fluidity of the membrane.
b.
Which of the following statements is CORRECT regarding transport across cell membranes? Both facilitated diffusion and active transport...
A. Use proteins to mediate transport across the cell membrane.
B. Can be mediated by ion channels.
C. Can generate electrical potentials across cells.
D. Require the solute to dissolve in the phospholipid bilayer.
E. Require energy from ATP.
A.
In the stages of cell signalling, the signalling molecule (e.g. hormone or neurotransmitter) is directly involved in...
A. Amplification of the signal in the cell.
B. Producing the 2nd messenger in the cell.
C. Transduction.
D. Activation of the cellular response.
E. Reception.
E.
Adrenaline is secreted from the adrenal medulla near the kidney and acts on the heart to increase heart rate. This is an example of which type of signalling?
A. Paracrine signalling by adrenaline.
B. Hormonal signalling by adrenaline carried in the blood.
C. Synaptic signalling by adrenaline released from nerves.
D. Local signalling by adrenaline in the heart.
E. Long‐distance signalling by nerves.
B.
Adrenaline is secreted from the adrenal medulla near the kidney and acts on the heart to increase heart rate. The effect of adrenaline on the heart...
A. Affects the activity of the enzyme cyclo-oxygenase.
B. Requires adrenaline to go into the heart cells by active transport.
C. Is mediated by a G protein‐coupled receptor.
D. Results in the production of the first messenger cyclic AMP.
E. Requires a change in only one protein in the heart cells to mediate the response.
C.
Which of the following is NOT a function of membrane proteins in cells?
A. Signal transduction.
B. Transport and enzymatic activity.
C. Attachment of the cytoskeleton and extracellular matrix.
D. Cell to cell recognition by glycoproteins.
E. Making membranes more fluid at low temperatures.
E.
Maintaining appropriate concentrations of ions across cell membranes is dependent on
A. The low water solubility of ions.
B. The presence of ion channels in the cell membrane.
C. Passive diffusion of ions across the membrane phospholipid bilayer.
D. Active transport via ion channels
E. Osmotic movement of water to the region of lower ion concentration.
B.
Which ONE of the following statements about
Na⁺/K⁺‐ATPase is INCORRECT? It...
A. Functions as an electrogenic pump.
B. Allows active transport of cations.
C. Uses energy from ATP breakdown.
D. Transports Na+ ions down the concentration gradient.
E. Works with the Na+‐glucose cotransporter for active uptake of glucose.
D.
G protein‐coupled receptors (GPCRs)...
A. Are not important for the action of chemicals released from neurons (neurotransmitters).
B. Have only 1 transmembrane spanning domain.
C. Have the fastest action of the super families of receptors.
D. Activate the production of a cascade of 2nd messenger molecules.
E. Include the insulin receptor.
D.
The concentrations of Na⁺ and K⁺ in the cytosol
and extracellular fluid are (in mM)...
A. 15, 150; 140, 5
B. 150, 10; 5, 140
C. 150, 5; 1, 10
D. 5, 10; 10, 140
E. 15, 150; 10, 100
A.
Activation of Na⁺/K⁺‐ATPase...
A. Is required to generate an action potential.
B. Decreases intracellular [K⁺].
C. Increases intracellular [Cl⁻].
D. Increases intracellular [Ca²⁺].
E. Decreases intracellular [Na⁺].
E.
Digoxin is used to inhibit Na⁺/K⁺‐ATPase in a toad sciatic nerve preparation. Which of the following would you NOT expect to occur in the neurons?
A. Na⁺ ion gradient gradually disappears.
B. K⁺ ion gradient gradually disappears.
C. Cl⁻ ion gradient gradually disappears.
D. Resting membrane potential is reduced.
E. Intracellular negative charge is decreased.
C.
The resting membrane potential of cells is NOT influenced by...
A. The activity of the sodium potassium pump.
B. The high membrane permeability of potassium ions.
C. Energy derived from ATP.
D. Voltage‐gated sodium channels.
E. The low membrane permeability of sodium ions.
D.
Voltage‐gated Na⁺ and K⁺ channels...
A. Are both activated by depolarization in the neuron.
B. Cause hyperpolarisation of neurons when they are activated.
C. Both cycle through three conformations during their activity.
D. Are both activated rapidly.
E. Increase intracellular [K⁺].
A.
The process for acetylcholine release from
motor neurons involves...
A. Opening of ligand‐gated calcium channels.
B. Acetylcholine‐receptor mediated formation of clathrin‐coated vesicles.
C. Phagocytosis.
D. Pinocyctosis.
E. Exocytosis.
E.
An EPSP occurred in a postsynaptic neuron in response to release of glutamate from a presynaptic neuron. What mechanism could explain this?
A. Activation of voltage‐gated sodium channels.
B. Activation of voltage‐gated potassium channels.
C. Activation of ligand‐gated sodium channels.
D. Activation of ligand‐gated chloride channels.
E. Inhibition of voltage‐gated sodium channels.
C.
Which statement about calcium ions is INCORRECT?
A. Resting intracellular Ca²⁺ concentration is 0.1 µM.
B. The Ca²⁺ gradient across cell membranes is about 10,000 fold.
C. Ca²⁺ enters neurons and stimulates exocytotic release of neurotransmitters.
D. Ca²⁺ enters presynaptic neurons via ligand‐gated Ca²⁺ channels.
E. Ca²⁺ is a second messenger in cells.
D.
Comparing postsynaptic potentials with action
potentials, which statement is CORRECT?
A. Both are "all or nothing".
B. Both are generated at the cell body.
C. Both travel along the axon.
D. Both can cause depolarisation of the neuronal membrane.
E. Both are inhibitory and cause hyperpolarisation.
D.
Which statement about 2nd messengers is INCORRECT? Second messengers...
A. Are always present in cells at the same concentration.
B. Mediate cell signalling when they are present.
C. Act as amplifiers when they are synthesised or released.
D. Have regulated mechanisms for their destruction or removal.
E. Include cyclic AMP and Ca²⁺.
A.
The release of noradrenaline from a presynaptic neuron in the brain stimulated postsynaptic B-adrenoceptors. This resulted in cyclic AMP synthesis and an inhibitory effect on the postsynaptic neuron. This is an example of...
A. Direct synaptic transmission.
B. Depolarisation of the postsynaptic neuron.
C. Cyclic AMP acting as a second messenger.
D. A response mediated by ligand‐ gated ion channels.
E. An amino acid acting as a neurotransmitter.
C.
The release of noradrenaline from a presynaptic neuron in the brain stimulated postsynaptic B‐adrenoceptors. This resulted in cyclic AMP synthesis and an inhibitory effect on the postsynaptic neuron. Removal of noradrenaline from the synaptic cleft...
A. Occurs rapidly by diffusion.
B. Involves metabolism by the enzyme acetylcholinesterase.
C. Requires rapid uptake by B‐ adrenoceptors.
D. Occurs primarily by uptake into glial cells.
E. Is mediated by re-uptake into the presynaptic neuron by a transporter.
E.
Passive diffusion...
A. Allows rapid passage of nutrients such as glucose across distances of centimeters.
B. Avoids the necessity to have a circulatory system.
C. Requires energy generated from ATP.
D. Mediates transfer of dissolved gases across epithelial cell membranes.
E. Is not an important mechanism in cells of mammalian systems.
D.
Which of the following is NOT a common feature of all respiratory systems?
A. Linked with a circulatory system for gas transport.
B. Large surface area for gas exchange.
C. Moist surface at which gas exchange occurs.
D. Specialized cell types for gas transfer.
E. Thin epithelial surfaces for gas exchange.
A.
In the pulmonary circulation...
A. Blood pressure is higher than in the systemic circulation.
B. The pulmonary vein carries oxygen poor blood.
C. Oxygen diffuses directly from air in the alveoli into the capillaries.
D. There is a very large capillary surface area.
E. A large of amount of water is lost by evaporation from the alveoli.
D.
In negative pressure ventilation...
A. Exhalation occurs when the diaphragm relaxes.
B. Inhalation occurs when pressure in the chest is higher than atmospheric.
C. The rib cage expands when rib muscles relax.
D. The pleural membranes cause pain if they move.
E. Elastic recoil of the lung tends to increase lung volume.
A.
Which of the following will NOT occur in response to an increase in blood CO2 levels?
A. Increase in blood pH.
B. Detection by sensors in the medulla oblongata.
C. Detection of pH change by sensors in the carotid arteries.
D. Change in pH of the cerebrospinal fluid.
E. Increase in respiratory rate.
A.
The human cardiovascular system...
A. Is an example of an open circulatory system.
B. Allows the transfer of nutrients across capillaries.
C. Allows mixing of O₂ rich and O₂ poor blood in the ventricles.
D. Is an example of a double circulation like that in fish.
E. Has the same pressure in the pulmonary and systemic circulations.
B.
What is the main advantage of a closed circulatory system?
A. It is easy to maintain.
B. No CO2 can enter the system.
C. It requires little energy.
D. It operates at low pressures.
E. It efficiently supports the high metabolic demand of tissues.
E.
Which one of the following statements about blood flowing into the right atria is incorrect?
A. It comes from the vena cava.
B. It is oxygen-poor.
C. It is about to flow into the right ventricle.
D. It is exiting the pulmonary circuit.
E. It is entering the atria during diastole.
D.
The pulmonary artery takes blood from:
A. Lungs to RV
B. LV to RV
C. RV to lungs
D. LV to lungs
E. Lungs to LV
C.
Blood returning to the mammalian heart in
a pulmonary vein will drain first into the:
A. Vena cava
B. Left atrium
C. Right atrium
D. Left ventricle
E. Right ventricle
B.
Which one of the following statements about the electrical activity of the heart is incorrect?
A. Cells in the SA node set the rate and timing for contraction of all cardiac muscle cells.
B. The ventricles and atria contract simultaneously.
C. The rate of contraction can be controlled by the autonomic nervous system.
D. Impulses are delayed at the AV node.
E. Impulses travel from the SA node to the AV node.
B.
The SA node is located in the:
A. RV
B. LV
C. RA
D. LA
E. Aorta
C.
Damage to the AV node would:
A. Increase blood flow from vena cava to right atrium.
B. Disrupt the rhythm of ventricular contractions.
C. Decrease the rate of atrial contractions.
D. Increase cardiac output.
E. Increase the force of ventricular contractions.
B.
What would be the long-term effect if the lymphatic
vessels associated with a capillary bed were blocked?
A. Fewer proteins would leak from the interstitial fluid into the blood.
B. Nothing would happen.
C. Fluid would accumulate in the interstitial areas.
D. Blood pressure in the capillary bed would decrease.
E. More fluid would enter the venous capillaries.
C.
G-protein coupled receptors differ from insulin receptors in all of the following ways EXCEPT:
A. The time required for an effect.
B. The mechanism by which they produce a response in a cell.
C. The role of phosphorylation in their cellular effects.
D. The receptors are on the cell surface.
E. The involvement of second messengers in their cellular effects.
D.
Insulin is released from the pancreas after a meal and reduces plasma glucose levels. Which mechanism is NOT involved in the action of insulin?
A. Phosphorylation of several targets inside liver cells.
B. Increased expression of glucose transporters in the pancreas.
C. Increased production of glycogen.
D. Increased expression of glucose transporters in the liver.
E. Stimulation of tyrosine kinase linked receptors.
B.
Steroid hormone receptors...
A. Are found inside cells.
B. Have no effects on expression of genes.
C. Mediate fast actions similar to ligand-gated ion channels.
D. Require their ligands to be water soluble.
E. Are coupled to heterotrimeric G-proteins.
A.
Vasopressin (ADH) is produced in the neurons of the hypothalamus and later secreted into the bloodstream before it finally reaches the kidneys. This is an example of...
A. Endocrine signalling.
B. Paracrine signalling.
C. Neuroendocrine signalling.
D. Autocrine signalling.
E. Synaptic signalling.
C.
Which of the following statements about hormones
is CORRECT?
A. Polypeptide hormones require special transport proteins in the bloodstream.
B. Steroid hormones have intracellular receptors in the cells from which they are released.
C. All amine hormones are made from cholesterol.
D. The receptors for polypeptide hormones are usually found on the cell surface of target cells.
E. Water soluble amine hormones usually have their receptors in the nuclei of target cells.
D.
Which of the following statements about homeostasis is INCORRECT? Homeostasis...
A. Results in an animal conforming to its external environment.
B. Depends on negative feedback mechanisms.
C. Refers to a steady-state balance of the internal environment.
D. Does not usually require positive feedback loops.
E. Allows fluctuation of the internal environment within a normal range.
A.
Your friend's mother has symptoms of losing weight and feeling hot and sweaty. It has been found that the symptoms are due to over activity of her thyroid gland. Which one of these possibilities would NOT be the cause?
A. Excess thyroid stimulating hormone release from the anterior pituitary.
B. Excessive growth of the thyroid gland due to a tumor.
C. Lack of function of a negative feedback mechanism.
D. Lack of function of a positive feedback mechanism.
E. Excess secretion of a tropic factor from the hypothalamus.
D.
Your friend's mother has symptoms of losing weight and feeling hot and sweaty. It has been found that the symptoms are due to over activity of her thyroid gland. The thyroid hormone is an example of a...
A. Steroid hormone.
B. Water soluble peptide hormone.
C. Lipid soluble amine hormone.
D. Soluble amine hormone.
E. Neurotransmitter.
C.
Your friend's mother has symptoms of losing weight and feeling hot and sweaty. It has been found that the symptoms are due to over activity of her thyroid gland. Why?
A. Thyroid hormone receptors are found only on the hypothalamus.
B. Thyroid hormone stimulates metabolism.
C. Thyroid hormone is required for a tadpole to develop into a frog.
D. Thyroid hormone is released in response to stress.
E. Thyroid hormone is important in embryonic development.
B.
What will NOT be likely to happen in response to this sudden stressful event?
A. Increase in activity of the sympathetic nervous system.
B. Increase in heart rate.
C. Decrease in blood flow to the intestine.
D. Release of glucose from glycogen stores in the liver.
E. Increase in activity of the parasympathetic nervous system.
E.
Matt's response to the appearance of the (scary/stressful) shark event will involve...
A. Only an endocrine response.
B. Only a nervous system response.
C. Only the central nervous system.
D. The nervous and endocrine systems.
E. Only the peripheral nervous system.
D.
Increased cardiac output in 'fight or flight' is mostly due to...
A. α-adrenoceptors binding adrenaline.
B. α-adrenoceptors binding noradrenaline.
C. β-adrenoceptors binding glutamate.
D. β-adrenoceptors binding adrenaline & noradrenaline.
E. Corticosteroids affecting the right ventricle.
D.
Which of the following is INCORRECT in relation to the adrenal glands?
A. They are found close to the kidney.
B. They release catecholamines and corticosteroids from the same cell type.
C. The immediate response to stress is mediated by catecholamines.
D. Corticosteroids mediate the long term response to stress.
E. They are stimulated by mechanisms involving the hypothalamus.
B.
Which of the following statements about the hypothalamus and pituitary gland is INCORRECT?
A. Neurons from the hypothalamus enter the posterior pituitary.
B. The pituitary is not a single organ.
C. Neural signals from the hypothalamus go to the adrenal medulla.
D. Endocrine signals from the hypothalamus go to the anterior pituitary.
E. Neurons from the hypothalamus enter the anterior pituitary.
E.
Adrenaline mediates a decrease in which of the following?
A. Uptake of glucose into liver cells.
B. Heart rate.
C. Blood flow to the lungs.
D. Blood flow to the brain.
E. Diameter of the airways.
A.
Which of the following factors would tend to increase membrane fluidity?
A. A greater proportion of unsaturated phospholipids.
B. A greater proportion of saturated phospholipids.
C. A lower temperature.
D. A relatively high protein content in the membrane.
E. A greater proportion of relatively large glycolipids compared to lipids having smaller molecular masses.
A.
In which one of the following solutions would red blood cells be most likely to burst?
A. 150 mM NaCl
B. 80 mM CaCl₂
C. 100 mM NaCl + 200 mM glucose
D. 50 mM NaCl + 200 mM Drug X (X = a small non‐polar molecule)
E. 300 mM NaCl
D.
Which of the following is NOT a characteristic of G protein‐coupled receptors? They..
A. Bind and activate heterotrimeric G proteins.
B. Are the most abundant type of receptor in our genome.
C. Are membrane proteins that are found only in the periphery.
D. Are major targets for the actions of clinically used drugs.
E. Generate amplified intracellular signals (e.g. cAMP and Ca²⁺).
C.
Insulin and glucagon have opposing effects on blood glucose levels. Which of the following is CORRECT regarding the receptors for insulin and glucagon?
A. Receptors for both insulin and glucagon have 7 transmembrane domains.
B. Receptors for both insulin and glucagon stimulate a cascade of phosphorylation.
C. Insulin receptor stimulation results in reduced glucose transport into cells.
D. Glucagon acts on a G‐protein coupled receptor and results in cAMP production.
E. The timescale for stimulation of both receptor types is minutes to hours.
E.
Blood pressure in capillary beds is closest to...
A. 120/80 mmHg
B. 100/30 mmHg
C. 100 mmHg
D. 0 mmHg
E. 30 mmHg
E.
Human airways...
A. Have a smaller surface area than the skin.
B. Allow gas exchange of O₂ and CO₂ by passive diffusion.
C. Provide O₂ to all tissues in the body by direct contact.
D. Have a partial pressure of O₂ at alveoli equal to that in air.
E. Terminate at the bronchioles.
B.
Consider the oxygen supply for humans compared
with fish. What proportion of available oxygen is normally extracted by humans compared with fish?
A. 25% from air and water.
B. 25% from air and 80% from water.
C. 100% from air and water.
D. 80% from air and 25% from water.
E. A greater proportion in warm climates than cool climates for both humans and fish.
B.
Consider the oxygen supply for humans compared
with fish. Which mechanism enables the fish to
extract more oxygen from water than humans
can from air?
A. Huge surface area of alveoli.
B. Large capillary network supplying the lungs.
C. Active transport of oxygen in gills of fish but not in human lungs.
D. Loss of water by evaporation.
E. Counter-current exchange between water flow and blood flow in the fish gills.
E.
Consider the oxygen supply for humans during intense exercise compared with at rest. Positive cooperativity that is a property of the binding of oxygen (O₂) to haemoglobin (Hb) does NOT cause...
A. Increased affinity of binding of the 4th O₂ than the 1st O₂ molecule.
B. Difficulty in supplying O₂ to muscles during intense exercise.
C. 75% saturation of Hb with O₂ in blood supplying tissues at rest.
D. 15‐25% saturation of Hb with O₂ in blood supplying tissues during exercise.
E. Hb to be more effective than myoglobin in supplying O₂ in exercise.
B.
Consider the oxygen supply for humans during intense exercise compared with at rest. Which of the following is NOT involved in regulating respiration to optimal levels in both situations?
A. High CO2 levels detected as decreased pH.
B. Receptors in the aorta and carotid arteries.
C. Cerebrospinal fluid pH detected in the medulla oblongata.
D. Homeostatic feedback to get respiration back to normal after exercise.
E. Low O₂ levels detected in the medulla oblongata.
E.
What is the osmolarity of a 250 mM aqueous KCl solution?
A. 250 ml
B. 250 mosmol l⁻¹
C. 500 mosmol l⁻¹
D. 750 mosmol l⁻¹
E. Isotonic
C.
Which of the following will least affect the latency
period between stimulation of a motor nerve and
measurement of contraction in the attached muscle?
A. Addition of a local anaesthetic.
B. Myelination of the neurons.
C. Temperature of the preparation.
D. Length of the motor nerve.
E. Muscle mass.
E.
Which of the following could act as a negative control
in an experiment investigating the effect of increased
stimulus frequency on muscle contractile force?
A. Contractile force at a passive force of 200 mN.
B. Contractile force following a single stimulus.
C. Contractile force after 10 pulses at a 1 msec interval.
D. Contractile force after 10 pulses at a 20 msec interval.
E. Contractile force after 10 pulses at a 100 msec interval.
B.
When writing a materials and methods section for the action potentials experiment, what is the important information required from the following?
A. That you used Ringers solution.
B. That you used frog Ringers solution.
C. That you used frog Ringers solution at 24C.
D. That you used frog Ringers solution at 24C in a plastic container.
E. That you used frog Ringers solution at 24C in a plastic container, filled from a storage container.
C.
Cell membranes have been described as 'fluid mosaics of lipids and proteins'. Which one of the following is NOT a property of cell membranes that fits with this description?
A. Fused rat and human cell membranes show mixing of marker proteins from the two species within a short time of the fusion, such as after 1 hour.
B. Phospoholipids in cell membranes move rapidly in a lateral direction, but not often in a flip-flop direction to the other side of the membrane.
C. Membrane-embedded glycoproteins are involved in cell-cell recognition.
D. Amphipathic phospholipids include a hydrophilic head in contact with extracellular fluid and a hydrophobic tail in contact with intracellular fluid.
E. The presence of unsaturated hydrocarbons increases the fluidity of cell membranes.
D.
Consider a patient who requires urgent treatment and you are contemplating injecting one of the following solutions intravenously. Which of the solutions would you recommend NOT to use because it would be the MOST likely to result in the patient's red blood cells bursting?
A. 300 mM glucose.
B. 100 mM NaCl + 40 mM of XCl₂ where X is a divalent ion.
C. 100 mM NaCl + 100 mM Drug Y (which is a small lipophilic molecule).
D. 100 mM NaCl + 75 mM glucose.
E. 150 mM NaCl.
C.
Which of the following is a characteristic feature of a transporter protein in a plasma membrane?
A. It has few, if any, hydrophobic amino acids.
B. It works against diffusion.
C. It exhibits specificity for a particular type of molecule.
D. It requires the expenditure of cellular energy to function.
E. It is a peripheral membrane protein.
C.
Which of the following statements regarding transport of molecules across cell membranes is CORRECT?
A. There is a specific protein transporter for oxygen molecules in all cells in the body.
B. Small, charged and polar molecules cross cell membranes readily by passive diffusion.
C. Transporters in cell membranes are involved in facilitated diffusion, but not active transport.
D. Water crosses cell membranes mainly via recently discovered channels called aquaporins.
E. Ion channels are required for active transport of Na+ ions and K+ ions across cell membranes.
D.
In the pancreas, insulin is released by beta cells in response to high plasma glucose levels and glucagon is released by alpha cells in response to low plasma glucose levels. Insulin and glucagon...
A. Are lipophilic molecules that diffuse across cell membranes to act on intracellular receptors.
B. Both increase the number of glucose transporters at the cell membrane.
C. Are hormones that are carried in the blood and act on cells distant from where they are released.
D. Activate (insulin) or inactivate (glucagon) intracellular proteins by phosphorylating tyrosine residues in the amino acid residues of the proteins.
E. Act locally on cells in the pancreas to affect glycogen and glucose metabolism.
C.
Insulin is released by beta cells in response to high plasma glucose levels and glucagon is released by alpha cells in response to low plasma glucose levels.
Glucagon acts on G-protein coupled glucagon receptors to produce cyclic AMP in its target cells.
Which of the following statements about insulin receptors and glucagon receptors is INCORRECT?
A. Insulin receptors mediate a faster response in cells than glucagon receptors.
B. Insulin receptors mediate a cascade of phosphorylation of proteins in cells.
C. Glucagon receptors bind to intracellular heterotrimeric G-proteins when they are activated.
D. Glucagon receptors mediate a cascade of activation of adenylate cyclase to produce the second messenger cyclic AMP.
E. Insulin receptors are tyrosine kinase linked receptors.
A.
The operation of the sodium-potassium "pump", also known as Na⁺/K⁺-ATPase, moves...
A. Sodium ions out of the cell and potassium ions into the cell against their concentration gradients.
B. Sodium ions and potassium ions into the cell against their concentration gradients.
C. Sodium and potassium ions into the cell using energy from cAMP.
D. Sodium and potassium ions out of the cell without requiring energy from ATP.
E. Sodium ions into the cell and potassium ions out of the cell, using energy from ATP.
A.
For a neuron with an initial membrane potential at -70 mV, an increase in the movement of potassium ions out of the cytoplasm of the neuron would result in...
A. Passive diffusion of additional potassium ions into the cell via the sodium-potassium pump to restore the initial conditions.
B. The replacement of potassium ions with sodium ions.
C. The replacement of potassium ions with calcium ions.
D. Depolarisation of the neuron.
E. Hyperpolarisation of the neuron.
E.
After the depolarisation phase of an action potential, the membrane potential decreases due to...
A. A decrease in the permeability of the membrane to potassium and chloride ions.
B. The opening of more voltage-gated sodium channels in addition to those that opened during depolarization.
C. The opening of ligand-gated sodium channels.
D. The opening of voltage-gated K+ ion channels and the inactivation of voltage-gated Na+ ion channels.
E. Inhibition of the Na+/K+-ATPase pump.
D.
Action potentials are normally carried in only one direction: from the axon hillock toward the axon terminals. If you experimentally depolarise the middle of the axon to threshold, using an electrical probe, then...
A. Two action potentials will be initiated, one going toward the axon terminal and one going back toward the hillock.
B. An action potential will be initiated and proceed only back toward the axon hillock.
C. An action potential will be initiated, but it will die out before it reaches the axon terminal.
D. No action potential will be initiated.
E. An action potential will be initiated and proceed only in the normal direction toward the axon terminal.
A.
Assume that a single EPSP has a positive magnitude of +1.5 mV at the axon hillock, and that a single IPSP has a negative magnitude of -1.0 mV. For a neuron with an initial membrane potential of -70 mV, the net effect of the simultaneous arrival of 6 EPSPs and 8 IPSPs would be to ___________ the membrane by moving its potential to ________ .
A. Slightly depolarise; -69 mV
B. Depolarise; +40 mV
C. Hyperpolarise; -78 mV
D. Slightly hyperpolarise; -72 mV
E. Depolarise; -61 mV
A.
You found the following in an experiment where you were testing refractory periods in a nerve preparation:
1. Keeping the usual stimulus strength, you could generate a 2nd action potential in the nerve if your stimulus frequency was every 5 milliseconds.
2. If you increased the stimulus strength, then you could generate a 2nd action potential with a second stimulus after 3 milliseconds.
3. If you used a stimulus frequency any faster than every 3 milliseconds, then you could not generate a 2nd action potential, irrespective of the stimulus strength you used.
Which of these conclusion is compatible with your experimental results in this nerve preparation?

A. The relative refractory period, where there are some voltage-gated Na+ channels that have closed again after being open for the action potential and inactivated, has a duration in this preparation of 2 milliseconds.
B. The absolute refractory period, when none of the voltage-gated Na+ channels have been through the stages of being inactivated and closed again, is 5 milliseconds in this preparation.
C. These results demonstrate why an action potential can travel in both directions when it is generated at the axon hillock, provided that a high frequency of stimulation is used.
D. The relative refractory period, with only some voltage-gated Na+ channels in the closed state again after the first action potential, has a duration of 8 milliseconds in this preparation.
E. The absolute and relative refractory periods are the same length, because voltage-gated Na+ channels are always in either an open or closed state.
A.
Which of the following activities would be associated with the parasympathetic division of the nervous system?
A. Increased metabolic rate and blood glucose levels.
B. Opening of the airways to allow increased O₂ intake.
C. Release of adrenaline from the adrenal medulla.
D. Increased digestion in the gastrointestinal tract.
E. Increased heart rate.
D.
The central nervous system integration of simple responses to stimuli, such as the patellar reflex, is accomplished by which of the following?
A. Neurons in the spinal cord.
B. Grey matter in the cerebellum.
C. Medulla oblongata in the brainstem.
D. Corpus callosum connecting the left and right cerebral hemispheres.
E. Hypothalamus which is part of the diencephalon.
A.
The divisions of the nervous system that usually have antagonistic, or opposing, actions are...
A. Central nervous system and peripheral nervous system.
B. Sympathetic and parasympathetic.
C. Motor and sensory.
D. Forebrain and hindbrain.
E. Presynaptic and postsynaptic.
B.
Which area of the brain is most intimately associated with unconscious homeostatic control of such functions as respiration and circulation?
A. Thalamus.
B. Cerebrum.
C. Cerebellum.
D. Medulla oblongata.
E. Hypothalamus.
D.
Dopamine is an example of a neurotransmitter that acts via indirect synaptic transmission when it is released from dopaminergic neurons in the brain. When dopamine is released from presynaptic neurons in different areas of the brain, it acts on postsynaptic D1-receptors which are linked to activation of adenylate cyclase, or on postsynaptic D2-receptors which are linked to inhibition of adenylate cyclase. Use this information and your knowledge of related areas to answer this question and the next question.
Based on the background information, which of the following is a CORRECT statement regarding transmission by these neurons?

A. D2-receptors mediate their effects by decreasing the levels of cyclic AMP in the postsynaptic neuron.
B. Dopamine is lipid soluble and diffuses into the cell membrane to act on the intracellular D1- and D2-receptors.
C. The postsynaptic D1-receptors are voltage-gated calcium channels.
D. Dopamine activates ligand-gated sodium channels on the postsynaptic membrane.
E. The events at this synapse are an example of electrical transmission.
A.
Dopamine is an example of a neurotransmitter that acts via indirect synaptic transmission when it is released from dopaminergic neurons in the brain. When dopamine is released from presynaptic neurons in different areas of the brain, it acts on postsynaptic D1-receptors which are linked to activation of adenylate cyclase, or on postsynaptic D2-receptors which are linked to inhibition of adenylate cyclase. Stimulating the D1-receptors results in depolarisation and stimulating the D2-receptors results in hyperpolarisation.
Based on the background information and also the additional information, which one of the following statements is CORRECT?

A. Dopamine is rapidly removed from the synaptic terminal by metabolism to inactive products.
B. Dopamine, glutamate and GABA all act on ligand-gated ion channels to cause very fast responses at neuronal synapses.
C. Dopamine acting on either D1-receptors or D2-receptors has its effects amplifiied in the cell by G-protein-mediated effects on the activity of adenylate cyclase.
D. The cell signalling mechanism activated by dopamine on D1-receptors is the same as that for glutamate acting on NMDA receptors in that it involves a G-protein.
E. The cell signalling mechanism activated by the D2-receptors is like that for GABAA receptors in that it involves the opening of ligand-gated chloride channels.
C.
John, aged 32 years old, has had debilitating symptoms for several months, and has undergone a range of diagnostic tests to determine the cause. He is diagnosed with multiple sclerosis, after detection of progressive demyelination of neurons in several parts of his nervous system over several months.
Considering John's case in the background material, you start to think about how neuronal conduction occurs normally. Which of the following statements about myelination and conduction of action potentials in neurons is INCORRECT?

A. Voltage-gated sodium channels that are required for conduction of an action potential are restricted to the nodes of Ranvier in a myelinated neuron.
B. Conduction of action potentials in myelinated neurons occurs much faster than in unmyelinated neurons of the same diameter.
C. Conduction of action potentials only occurs at the nodes of Ranvier between the myelin sheaths.
D. Action potentials are generated across the neuronal membrane in the myelinated region, despite the electrical insulation provided by the Schwann cells.
E. Action potentials are propagated along a myelinated neuron by saltatory conduction.
D.
John, aged 32 years old, has had debilitating symptoms for several months, and has undergone a range of diagnostic tests to determine the cause. He is diagnosed with multiple sclerosis, after detection of progressive demyelination of neurons in several parts of his nervous system over several months.
Considering the effects of the demyelination of some neurons in John's nervous system, you would expect action potentials in the damaged neurons...

A. To be propagated by passive diffusion of sodium and potassium ions across the neuronal membrane.
B. To occur only after expression of new voltage-gated sodium and potassium potentials in the regions between the nodes of Ranvier.
C. To be conducted more rapidly than in the normal neurons.
D. To be prolonged due to inactivation of voltage-gated potassium channels.
E. Not to be propagated effectively because of loss of the electrical insulating properties of the Schwann cells.
E.
During the process of skeletal muscle contraction, energy released by the hydrolysis of adenosine triphosphate (ATP) is required for...
A. Release of the bound myosin heads from actin molecules
B. Converting the myosin heads from their low-energy configuration to their high-energy configuration
C. Altering the conformation of tropomyosin molecules
D. Generating the powerstroke to slide myofilaments relative to each other
E. Attaching myosin heads to actin binding sites
B.
A sarcomere can be described as...
A. A specialised contractile unit of smooth muscle.
B. The distance between the M-line and the Z-line.
C. The distance between two consecutive Z-lines.
D. A contractile unit of muscle that comprises predominantly myosin and collagen filaments.
E. The length of two I-zones minus the length of the A-zone.
C.
Which of the following statements concerning skeletal muscle(s) is CORRECT?
A. Muscle overstretch is resisted by tension in the passive connective tissue components of the belly.
B. In elbow flexion, biceps brachii acts eccentrically.
C. Isotonic activity is when a muscle remains at a constant length when active.
D. The amount of force that a muscle produces is unrelated to sarcomere length.
E. Postural muscles contain a high proportion of Type II fibres.
A.
The osteological features that allow osteocytes to communicate with each other are called...
A. Canaliculi.
B. T-tubules.
C. Chondrocytes.
D. Lacunae.
E. Primary osteons.
A.
Considering bone, which one of the following statements is CORRECT?
A. Trabecular bone remodelling involves formation of Haversian systems.
B. Osteoblasts produce osteoid that mineralises to become bone.
C. Osteocytes within compact bone communicate with their neighbours via cytoplasmic extensions that pass through central canals.
D. Primary osteons result from bone remodelling.
E. Trabecular bone and compact bone have the same mechanical properties.
B.
Which of the following statements about human walking is INCORRECT?
A. The maximum walking speed is inversely proportional to lower limb length.
B. Graviportal (cursorial) locomotion occurs, as the knee of the load-bearing limb is in an extended position at mid-stance.
C. Bipedal locomotion in hominins is thought to have arisen over 3.5 million years ago.
D. There is always contact between one or two feet and the ground.
E. The maximum speed of walking on the Moon would be considerably slower than on the Earth.
A.
You are presented with five bones of different sizes and shapes and are asked to predict which of these has the greatest resistance to bending. On looking at the cross-sections of the specimens at the same relative point along their length (e.g. mid-shaft), you note that they all have the same amount of bone in the cross-section, but the distribution of bone varies.
If the neutral axis is considered as a horizontal line, which of the following cross-sectional morphologies would be expected to have the greatest resistance to bending?
A. A hollow, oval bone with the greatest diameter perpendicular to the neutral axis with uniformly 2 mm-thick walls.
B. A hollow, circular bone with uniformly 2 mm-thick walls.
C. A hollow, oval bone with the greatest diameter parallel to the neutral axis with uniformly 5 mm-thick walls.
D. A hollow, circular bone with uniformly 5 mm-thick walls.
E. A solid cylinder of bone.
A.
Which of the following statements regarding transfer of gases in different species is CORRECT?
A. Systems for extraction of O₂ need to be much more efficient in terrestrial animals than in aquatic species such as fish.
B. In human lungs, the huge surface area of the alveoli allows transfer of O₂ and CO₂ by direct contact with the pulmonary artery.
C. The tracheal systems of insects and the lungs of vertebrates require the circulation to deliver O₂ to tissues.
D. O₂ availability for marine species decreases as the temperature and salinity of water increases.
E. O₂ and CO₂ transfer across membranes is dependent on active transport in vertebrates.
D.
Mammals ventilate their lungs through negative pressure ventilation. Which one of the following statements about negative pressure ventilation is INCORRECT?
A. Air enters the lungs when the pressure inside the lungs is lower than atmospheric pressure.
B. Inhalation is an active process.
C. Exhalation occurs when the rib muscles and diaphragm relax.
D. Air is pushed into the lungs by forced airflow.
E. Changes in thoracic cavity volume are paralleled by changes in lung volume due to the presence of the double membrane pleural sac.
D.
Which of the following statements about haemoglobin is CORRECT?
A. Binding of oxygen to a subunit of haemoglobin induces a conformational change that aids the binding of an additional oxygen molecule.
B. Haemoglobin exhibits negative cooperativity in oxygen binding.
C. The higher the pO2, the less oxygen will be bound to haemoglobin.
D. Haemoglobin is a protein made up of two polypeptide subunits.
E. Oxygen binding to haemoglobin is enhanced in the presence of high levels of CO2, due to the resulting decrease in pH.
A.
Which of the following statements about blood in the mammalian pulmonary vein is CORRECT?
A. It is about to flow into the right atrium.
B. It is entering the pulmonary circuit.
C. It is oxygen poor.
D. It will enter the left atrium during systole.
E. It will be returned to the heart before being pumped to the systemic circulation.
E.
Sarah Sprinter is a UQ track athlete, who is training for the upcoming University Games. At rest, Sarah's heart rate is 60 beats per minute and her stroke volume is 70 mL per beat. During a race, Sarah's heart rate increases to 120 beats per minute and her cardiac output is 20.4 litres per minute.
What is Sarah's stroke volume whilst racing?
A. 170 L per beat
B. 170 mL per beat
C. 198 mL per beat
D. 356 mL per beat
E. 70 mL per beat
B.
Which of the following statements about blood vessels is INCORRECT?
A. Arteries and veins have three layers surrounding the lumen.
B. Both arteries and veins contain valves.
C. Veins contain an endothelial cell layer.
D. An endothelial cell layer is present in the capillaries.
E. Arteries contain a thicker smooth muscle layer compared with veins.
B.
What would be the long-term effect if the lymphatic vessels associated with a capillary bed were blocked?
A. More fluid would enter the venous capillaries.
B. Fluid would accumulate in the interstitial areas.
C. Blood pressure in the capillary bed would decrease.
D. Fewer proteins would leak from the interstitial fluid into the blood.
E. Nothing would happen.
B.
Which ONE of the following best describes the series of events, in order, that occurs during the clotting process?
A. Endothelial damage; exposure of connective tissue; adhesion and activation of platelets; release of clotting factors; conversion of fibrinogen to fibrin.
B. Adhesion and activation of platelets; endothelial damage; conversion of fibrinogen to fibrin; exposure of connective tissue.
C. Endothelial damage; exposure of connective tissue; adhesion and activation of platelets; conversion of fibrinogen to fibrin; release of clotting factors.
D. Exposure of connective tissue; release of clotting factors; adhesion and activation of platelets; conversion of fibrinogen to fibrin.
E. Release of clotting factors; exposure of connective tissue; adhesion and activation of platelets; conversion of fibrinogen to fibrin.
A.
In fatty liver disease, the levels of a plasma protein named plasma protein C are elevated. How will this affect capillary function? It will
A. Increase fluid movement into the capillary at the venous end.
B. Reduce lymphatic flow.
C. Not affect capillary function.
D. Increase fluid movement out of the capillary at the arteriolar end.
E. Decrease fluid movement out of the capillary at the venous end.
A.
May Chang has had a difficult and stressful semester as she copes with her university studies in science and also dealing with her mother's diagnosis with a serious illness and looking after her 3 younger brothers while her father is working overseas. As the time for the end of semester examinations (including BIOL1040) approaches, she is feeling even more stressed.
Just before her BIOL1040 examination, May tells her friend 'my heart is thumping really hard inside my chest'. Which one of the following would NOT be contributing to this effect that May is experiencing?

A. Acetylcholine released from parasympathetic nerves causing increased contraction of cardiac muscle.
B. An increase in heart rate due to increased sympathetic nerve stimulation of the sinoatrial node.
C. Adrenaline and noradrenaline acting to increase the force of contraction of the heart.
D. Decreased stimulation of parasympathetic nerves that supply the sinoatrial node.
E. Adrenaline released into the circulation from the adrenal medulla.
A.
May Chang has had a difficult and stressful semester as she copes with her university studies in science and also dealing with her mother's diagnosis with a serious illness and looking after her 3 younger brothers while her father is working overseas. As the time for the end of semester examinations (including BIOL1040) approaches, she is feeling even more stressed.
During this stressful situation, May wants more of her cardiac output to reach her brain and little to go to her digestive tract. If this were to occur, which ONE of the following statements is ideal for the situation?

A. Vasodilatation in brain capillaries.
B. Constriction of pre-capillary sphincters in brain capillaries.
C. Vasodilatation in stomach capillaries.
D. Contraction of smooth muscle in brain venules.
E. Contraction of smooth muscle in brain arterioles.
A.
May Chang has had a difficult and stressful semester as she copes with her university studies in science and also dealing with her mother's diagnosis with a serious illness and looking after her 3 younger brothers while her father is working overseas. As the time for the end of semester examinations (including BIOL1040) approaches, she is feeling even more stressed.
May is particularly stressed just before she enters the room for her BIOL1040 examination and starts hyperventilating, with an increased rate and force of breathing, resulting in decreased blood CO2 levels.
Which of the following will occur as a result of this hyperventilation?

A. Reduced O₂ carrying capacity of haemoglobin at any given partial pressure of O₂.
B. Detection of the decreased blood CO2 levels by chemoreceptors in the aorta and carotid arteries.
C. Increased ventilation when the change in CO2 levels are detected by the medulla oblongata.
D. Decreased pH of the blood.
E. Increased CO2 levels in body tissues above the usual level of about 46 mmHg.
B.
Which one of the following is a mismatch between the hormone and its type or class?
A. Adrenaline (epinephrine) - Steroid hormone.
B. Glucocorticoids - Steroid hormones.
C. Vasopressin - Polypeptide hormone.
D. Insulin - Polypeptide hormone.
E. Thyroxine (thyroid hormone) - Amine hormone.
A.
Which of the following statements about the mineralocorticoid steroid hormone, aldosterone, is INCORRECT? Aldosterone...
A. Is produced from the parent molecule cholesterol.
B. Is involved in the regulation of salt metabolism.
C. Utilises cyclic-AMP as a second messenger.
D. Can have intracellular receptors.
E. Is secreted from the adrenal cortex.
C.
Vasopressin is released into the blood stream in response to which ONE of the following?
A. When kidneys detect high blood volume.
B .When the osmolarity of blood decreases.
C. Reduced salt intake.
D. Dehydration.
E. When osmoreceptor cells of the hypothalamus are inactive or not responding.
D.
Which ONE of the following statements is INCORRECT in relation to the posterior pituitary hormones?
A. Posterior pituitary hormones are non-tropic hormones.
B. Posterior pituitary hormones are synthesised by specialised cells in the posterior pituitary.
C. Posterior pituitary tumors can lead to decreased blood osmolarity.
D. Hormones from the posterior pituitary are polypeptide hormones.
E. There are only two (2) hormones that are released from the posterior pituitary.
B.
Which ONE of the following is an INCORRECT pairing of a type of signalling with the type of signalling molecule involved?
A. Endocrine signalling and hormones.
B. Synaptic signalling and phytohormones.
C. Paracrine signalling and local regulators.
D. Autocrine signalling and local regulators.
E. Neuroendocrine signalling and neurohormones.
B.
Which of the following are products of the light reactions of photosynthesis that are utilised in the Calvin cycle?
A. ADP, Pi, and NADP⁺.
B. H₂O and O₂.
C. ATP and NADPH.
D. CO2 and glucose.
E. Electrons and H⁺.
C.
One important difference between the anatomy of roots and the anatomy of leaves is that...
A. Only leaves have phloem and only roots have xylem.
B. A waxy cuticle covers leaves but is absent in roots.
C. The cells of roots have cell walls and leaf cells do not.
D. Leaves have epidermal tissue but roots do not.
E. Vascular tissue is found in roots but is absent from leaves.
B.
According to the ABC model of floral development, which genes would be expressed in a showy ornamental flower with multiple sepals and petals but no stamens or carpels?
A. A and C genes only.
B. A genes only.
C. B genes only.
D. C genes only.
E. A and B genes only.
E.
A water molecule could move all the way through a plant from soil to root to leaf to air and pass through a living cell only once. This living cell would be a part of which structure?
A. A guard cell.
B. The root cortex.
C. The Casparian strip.
D. The root epidermis.
E. The endodermis.
E.
Transpiration in plants requires all of the following EXCEPT...
A. Transport through xylem vessels.
B. Adhesion of water molecules to cellulose.
C. Cohesion between water molecules.
D. Active transport through xylem cells.
E. Evaporation of water molecules.
D.
The ripening of fruit and the dropping of leaves and fruit are principally controlled by...
A. Cytokinins.
B. Auxins.
C. Ethylene.
D. Indole acetic acid.
E. Carbon dioxide concentration (in air).
C.
A flash of red light followed by a flash of far-red light given during the middle of the night to a short-day plant will likely...
A. Convert florigen to the active form.
B. Cause increased flower production.
C. Have no effect upon flowering.
D. Stimulate flowering.
E. Inhibit flowering.
C.
Visible light is involved in many plant processes. Red light plays an active role in all of the following EXCEPT...
A. Phytochrome regulation.
B. Photosynthesis.
C. Phototropism.
D. Photomorphogenesis.
E. Photoperiod response.
C.
Farmer Ted has had problems with his vegetable crops, especially his tomatoes, recently, because they are now growing in the partial shade of a large shed built on the neighbouring farm. An agricultural advisor that Ted talks to suggests that the poor crop of tomatoes could be due to 'hormone issues' due to the inconsistent exposure of his plants to light. Ted is also aware that he is stressed and that may involve release of hormones in his system as well.
Answer the following questions based on this information.
Which ONE of the following statements does NOT apply to hormones in both plants and humans?

A. Hormones act on specific receptors on the cells from which they are secreted.
B. Hormones are often involved in negative feedback regulation.
C. Hormones involve long distance regulation.
D. Hormones are important for the maintenance of homeostasis.
E. Hormones are secreted by a cell and act on distant target cells.
A.
Farmer Ted has had problems with his vegetable crops, especially his tomatoes, recently, because they are now growing in the partial shade of a large shed built on the neighbouring farm. An agricultural advisor that Ted talks to suggests that the poor crop of tomatoes could be due to 'hormone issues' due to the inconsistent exposure of his plants to light. Ted is also aware that he is stressed and that may involve release of hormones in his system as well.
Answer the following questions based on this information.
Plant hormones can be characterised by all of the following EXCEPT that they...

A. Have a multiplicity of effects.
B. Affect division, elongation and differentiation of cells.
C. May act by altering gene expression.
D. Control plant growth and development.
E. Function independently of other hormones.
E.
Farmer Ted has had problems with his vegetable crops, especially his tomatoes, recently, because they are now growing in the partial shade of a large shed built on the neighbouring farm. An agricultural advisor that Ted talks to suggests that the poor crop of tomatoes could be due to 'hormone issues' due to the inconsistent exposure of his plants to light. Ted is also aware that he is stressed and that may involve release of hormones in his system as well.
Answer the following questions based on this information.
The tomato plants growing in a partially dark environment will grow toward light in a response called phototropism. Choose the INCORRECT statement regarding phototropism.

A. Phototropism is caused by a chemical signal.
B. Auxin causes a growth increase on one side of the stem.
C. Auxin causes a decrease in growth on the side of the stem exposed to light.
D. Removing the apical meristem prevents phototropism.
E. One chemical involved in phototropism is auxin.
C.
Farmer Ted has had problems with his vegetable crops, especially his tomatoes, recently, because they are now growing in the partial shade of a large shed built on the neighbouring farm. An agricultural advisor that Ted talks to suggests that the poor crop of tomatoes could be due to 'hormone issues' due to the inconsistent exposure of his plants to light. Ted is also aware that he is stressed and that may involve release of hormones in his system as well.
Answer the following questions based on this information.
Farmer Ted's plants in the shade will also use the "shade avoidance" response to attempt to find more light. This response is

A. A blue light response, involving more root branching to seek additional nutrients.
B. A blue light response, involving more stomatal opening.
C. A phytochrome Red-mediated response, in which the plant will flower earlier.
D. A phytochrome Red-mediated response, involving more stem branching.
E. A phytochrome Far Red-mediated response, in which the plant will grow taller.
E.
Farmer Ted has had problems with his vegetable crops, especially his tomatoes, recently, because they are now growing in the partial shade of a large shed built on the neighbouring farm. An agricultural advisor that Ted talks to suggests that the poor crop of tomatoes could be due to 'hormone issues' due to the inconsistent exposure of his plants to light. Ted is also aware that he is stressed and that may involve release of hormones in his system as well.
Answer the following questions based on this information.
Which of the following will NOT be occurring to Ted in the stressful situation he is experiencing?

A. The hypothalamus sends neural signals to the adrenal gland for the release of adrenaline.
B. Corticosteroids are released from the adrenal cortex.
C. The hypothalamus releases corticotropin releasing hormone (CRH).
D. The hypothalamus sends neural signals to the anterior pituitary for the release of adrenocorticotropic hormone (ACTH).
E. Catecholamines are released from the adrenal medulla.
D.
Farmer Ted has had problems with his vegetable crops, especially his tomatoes, recently, because they are now growing in the partial shade of a large shed built on the neighbouring farm. An agricultural advisor that Ted talks to suggests that the poor crop of tomatoes could be due to 'hormone issues' due to the inconsistent exposure of his plants to light. Ted is also aware that he is stressed and that may involve release of hormones in his system as well.
Answer the following questions based on this information.
Which of the following statements is CORRECT about the effect of adrenaline on Ted when it is released due to his stress? Adrenaline

A. Acts on α-adrenoceptors in skeletal muscle to increase the diameter of the blood vessels.
B. Acts on α-adrenoceptors in the intestinal blood vessels to increase the diameter of the vessels.
C. Acts on β-adrenoceptors in the liver to decrease glucose production from glycogen.
D. Acts on β-adrenoceptors in the heart to increase cardiac output.
E. Acts on α-adrenoceptors in the liver to increase glucose production from glycogen.
D.
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