MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 697 Mcqs, each offering curated multiple-choice questions to sharpen your Biology knowledge and support exam preparation. Choose a topic below to get started.
| 301. |
Regarding equilibrium potential (mammalian spinal motor neurons) |
| A. | The resting membrane potential is 70 mV identical to that of Ecl |
| B. | Equilibrium potential of potassium is +90 mV |
| C. | Increases in external sodium concentrations decrease the resting membrane potential |
| D. | Equilibrium potential of sodium is 60 mV |
| E. | Na+K+ ATPase pumps 2 sodium out of cell for every 3 potassium it pumps in |
| Answer» B. Equilibrium potential of potassium is +90 mV | |
| 302. |
The following are NOT energy sources of muscle: |
| A. | phosphorylcreatine |
| B. | fatty acids |
| C. | glucose |
| D. | glycogen |
| E. | creatine |
| Answer» F. | |
| 303. |
Which statement about blood flow is FALSE? |
| A. | cardiac output = stroke volume x heart rate |
| B. | the volume of blood pumped through the lungs equals the volume entering the heart |
| C. | Poiseville s Law predicts the effects of pressure and resistance on cardiac output |
| D. | the resistance of the systemic circulation is 5 to 10 times the pulmonary vascular resistance |
| E. | with constant pressure, a vessel with radius 2X has 16 times the flow of vessel with radius X |
| Answer» C. Poiseville s Law predicts the effects of pressure and resistance on cardiac output | |
| 304. |
Regarding haemodynamic principles, which statement is FALSE? |
| A. | viscosity of blood with haematocrit of 40 is three times that of water |
| B. | arterial blood volume is 10-15% total volume |
| C. | elastance measures a vessel s stiffness or recoil |
| D. | aging causes increased elastance and therefore decrease in resting (unstressed) arterial volume |
| E. | an increase in total peripheral resistance leads to increased arterial volume and BP |
| Answer» E. an increase in total peripheral resistance leads to increased arterial volume and BP | |
| 305. |
On which of the following does aldosterone exert its greatest effect? |
| A. | glomerulus |
| B. | proximal tubule |
| C. | thin portion of loop of Henle |
| D. | thick portion of look of Henle |
| E. | cortical collecting system |
| Answer» F. | |
| 306. |
Which statement about factors affecting blood pressure is FALSE? Factors that increase blood pressure are: |
| A. | increased heart rate |
| B. | increased blood volume |
| C. | pressure rises in increased cardiac output until the amount entering the arterial system equals the amount leaving |
| D. | increased total peripheral resistance |
| E. | increased end systolic volume |
| Answer» F. | |
| 307. |
Unmyelinated neurons: |
| A. | do not have Schwann cells associated with them |
| B. | display salutatory conduction |
| C. | constitute most of the cell population in the human central nervous system |
| D. | do not occur in humans |
| E. | none of the above are true |
| Answer» F. | |
| 308. |
Which of the following is NOT synthesised in post-ganglionic sympathetic neurons: |
| A. | L-dopa |
| B. | dopamine |
| C. | noradrenaline |
| D. | adrenaline |
| E. | acetylcholine |
| Answer» D. adrenaline | |
| 309. |
Plasma lipids and lipid transport: |
| A. | apoprotein B48 occurs in VLDL |
| B. | apoprotein B166 and apoprotein C occurs in chylomicrons |
| C. | lecithin cholesterol acyltrasferase is responsible for transferring cholesterol esters from HDL to |
| D. | chylomicron remnants travel from the intestine within lymphatic fluid in the thoracic duct |
| E. | one half of all LDL molecules is taken up by macrophages and other cells by means other than the LDL receptor |
| Answer» D. chylomicron remnants travel from the intestine within lymphatic fluid in the thoracic duct | |
| 310. |
In which body compartment is the bicarb buffering system least important? |
| A. | intracellular |
| B. | interstitial |
| C. | CSF |
| D. | blood |
| E. | collecting duct |
| Answer» B. interstitial | |
| 311. |
The distal tubule: |
| A. | absorbs most of the filtered sodium ions in the presence of aldosterone |
| B. | absorbs glucose in the normal state |
| C. | absorbs most of the filtered water in the presence of ADH |
| D. | secretes hydrogen via secondary active transport |
| E. | is almost entirely impermeable to urea |
| Answer» F. | |
| 312. |
The renal tubule: |
| A. | all sections are lined with cuboidal epithelial cells with luminal microvilli |
| B. | the thick loop of Henle rises to lie adjacent to its glomerulus |
| C. | there are a greater number of juxtamedullary nephrons than cortical |
| D. | the lacis cells of the juxtaglomerular apparatus secrete renin |
| Answer» C. there are a greater number of juxtamedullary nephrons than cortical | |
| 313. |
Which of the following does NOT increase renal tubular sodium reabsorption? |
| A. | cortisol |
| B. | oestrogen |
| C. | growth hormone |
| D. | insulin |
| E. | glucagon |
| Answer» F. | |
| 314. |
In skeletal muscle relaxation: |
| A. | there is a spread of depolarisation along T tubules |
| B. | Ca2+ is released from troponin |
| C. | there is increase Na+ and K+ conduction in the end plate membranes |
| D. | a resting membrane potential of -65mV is finally reached |
| E. | Mg2+ has a crucial role |
| Answer» C. there is increase Na+ and K+ conduction in the end plate membranes | |
| 315. |
Which of the following statements regarding renal tubular glucose absorption is INCORRECT? |
| A. | binds to SGLT-2 in luminal membrane |
| B. | example of secondary active transport |
| C. | transported out of luminal cell by GLUT-2 |
| D. | about 100% reabsorption in proximal tubule if less than transport maximum |
| E. | linked to sodium reabsorption |
| Answer» B. example of secondary active transport | |
| 316. |
With regard to skeletal muscle, which is INCORRECT? |
| A. | the terminal cisterns of sarcoplasmic reticulum lie in contact with T tubules |
| B. | the T tubules surround the muscle at its Z lines |
| C. | the Z line lies within the I band |
| D. | the M line is due to a central bulge in each of the thick filaments |
| E. | the area between two adjacent Z lines is called a sarcomere |
| Answer» C. the Z line lies within the I band | |
| 317. |
Which of the following is an example of a low energy phosphate compound: |
| A. | creatine phosphate |
| B. | UTP |
| C. | acetyl CoA |
| D. | glucose-6 phosphate |
| E. | ATP |
| Answer» E. ATP | |
| 318. |
Which glucose transporter is responsible for insulin-mediated glucose uptake in striated muscle and adipose tissue? |
| A. | glut 1 |
| B. | glut 2 |
| C. | glut 3 |
| D. | glut 4 |
| E. | glut 5 |
| Answer» E. glut 5 | |
| 319. |
Regarding the physical characteristics of the circulation: |
| A. | arterioles have a strong muscular wall but can close completely |
| B. | the arterial system contains the greatest volume of blood at any given time |
| C. | the aorta has a greater total cross sectional area than the venae cavae |
| D. | velocity is directly proportional to the cross sectional area of the blood vessel |
| E. | Reynold s number represents a measure of laminar blood flow |
| Answer» B. the arterial system contains the greatest volume of blood at any given time | |
| 320. |
Which is NOT correct about reflex mechanisms acting on the circulation? |
| A. | the baroreceptors in the carotid bodies are stimulated when blood pressure increases |
| B. | the Bainbridge reflex causes increase in heart rate |
| C. | the Cushing reflex is a special central nervous system ischaemic response resulting from increased intracranial pressure |
| D. | the maximum firing per change in pressure of the carotid baroreceptors occurs at a mean arterial pressure of 90mmHg |
| E. | the glossopharyngeal nerve is involved in baroreceptor reflex system |
| Answer» B. the Bainbridge reflex causes increase in heart rate | |
| 321. |
Regarding volumes in each compartment, which is FALSE? |
| A. | 3% in LV and aorta |
| B. | 15% in arterial system |
| C. | 7% in capillaries |
| D. | 50% in venous system (systemic) |
| E. | 40% in pulmonary circulation |
| Answer» F. | |
| 322. |
Regarding pressures, which is FALSE? |
| A. | lateral (static) pressure is reduced but prolonged by elastic arteries |
| B. | static pressure increases with gravitation (hydrostatic) pressure increases |
| C. | static pressure does not include kinetic energy |
| D. | greater resistance to flow through a segment of circulation leads to greater loss of energy through that segment |
| E. | kinetic energy becomes more significant in a narrowed segment and converts back to potential energy when the tube widens |
| Answer» C. static pressure does not include kinetic energy | |
| 323. |
Regarding body water, which is FALSE? |
| A. | 1/3 total body weight is extra and 2/3 intra cellular |
| B. | 60% of body weight is water |
| C. | plasma is 8% and total blood 10%, of body weight |
| D. | of extracellular fluid, 25% is vascular, 75% extravascular |
| E. | interstitial fluid is 15% of body weight |
| Answer» D. of extracellular fluid, 25% is vascular, 75% extravascular | |
| 324. |
Regarding flow, which is FALSE? |
| A. | flow is proportional to pressure gradient |
| B. | flow is inversely proportional to resistance |
| C. | Poiseville s Law relates flow to pressure gradient and factors that influence resistance |
| D. | Poiseville Law demonstrates that resistance to flow is largely determined by viscosity and length of tube and radius x 4 |
| E. | if radius of a vessel is halved, the flow may be reduced to 1/16th of previous flow |
| Answer» E. if radius of a vessel is halved, the flow may be reduced to 1/16th of previous flow | |
| 325. |
Which substance is 60 times more concentrated in urine than in plasma? |
| A. | glucose |
| B. | creatinine |
| C. | sodium |
| D. | urea |
| Answer» E. | |
| 326. |
The molecular mass of a substance is expressed in: |
| A. | moles |
| B. | Daltons |
| C. | equivalents |
| D. | osmoles |
| E. | grams |
| Answer» C. equivalents | |
| 327. |
Trace elements believed essential to life include all EXCEPT: |
| A. | arsenic |
| B. | cyanide |
| C. | cobalt |
| D. | silicon |
| E. | nickel |
| Answer» C. cobalt | |
| 328. |
Na+ / K+ ATPase pump which is FALSE? |
| A. | it is electrogenic in nature |
| B. | it is important in maintaining cell volume |
| C. | plays a major role in secondary active transport |
| D. | it is the main factor which determine the resting membrane potential |
| E. | it is an example of primary active transport |
| Answer» E. it is an example of primary active transport | |
| 329. |
Na+ -K+ -ATPase is an example of a/an: |
| A. | symport |
| B. | uniport |
| C. | biport |
| D. | antiport |
| E. | airport |
| Answer» E. airport | |
| 330. |
The Na+ K+ ATPase pump: |
| A. | utilises ATP to pump out 2 Na+ ions for every 3 K+ ions |
| B. | activity is altered by insulin, aldosterone and thyroid hormones |
| C. | is only found in muscle and nervous tissue |
| D. | is made of , , and subunits |
| E. | ATP binds to the subunit causing a protein configuration change |
| Answer» C. is only found in muscle and nervous tissue | |
| 331. |
Substance P: |
| A. | is a carbohydrate |
| B. | is a polypeptide found in the intestine and nervous tissue |
| C. | is a II amino acid residue mainly found in the liver |
| D. | is not involved in the neuroendocrine system |
| E. | is a lipid |
| Answer» C. is a II amino acid residue mainly found in the liver | |
| 332. |
Total lung capacity is equal to: |
| A. | vital capacity + tidal volume |
| B. | vital capacity + functional residual capacity |
| C. | tidal volume + residual volume |
| D. | functional residual capacity + tidal volume |
| E. | vital capacity + residual volume |
| Answer» F. | |
| 333. |
Lung compliance increases with: |
| A. | asthma |
| B. | alveolar oedema |
| C. | pulmonary hypertension |
| D. | atelectasis |
| E. | pulmonary fibrosis |
| Answer» B. alveolar oedema | |
| 334. |
Increased lung compliance is associated with: |
| A. | increasing age |
| B. | increasing pulmonary venous pressure |
| C. | high expanding pressures |
| D. | interstitial fibrosis |
| E. | low lung volumes associated with hypoventilation |
| Answer» B. increasing pulmonary venous pressure | |
| 335. |
Regarding the elastic properties of the lung: |
| A. | the lung volume at any given pressure during inflation is larger than during deflation |
| B. | the area under the pressure-volume curve is known as the compliance |
| C. | surface tension is the force acting across an imaginary line in the surface of the liquid |
| D. | pressure generated in an alveolus equals 4T/R |
| E. | surfactant, produced by Type I alveolar cells, reduces surface tension in alveoli |
| Answer» D. pressure generated in an alveolus equals 4T/R | |
| 336. |
Metabolic functions of the lung include all of the following EXCEPT: |
| A. | conversion of AI to AII by ACE |
| B. | metabolism of AII |
| C. | inactivation of bradykinin |
| D. | removal of serotonin |
| E. | metabolism of arachidonic acid metabolises |
| Answer» C. inactivation of bradykinin | |
| 337. |
All of the following shift the Hb dissociation curve to the right during exercise EXCEPT: |
| A. | increased 2,3 DPG |
| B. | increased pCO2 |
| C. | increased temperature |
| D. | decreased pO2 |
| E. | increased H+ concentration |
| Answer» E. increased H+ concentration | |
| 338. |
The effects of hyperthyroidism on the cardiovascular system include all of the following EXCEPT: |
| A. | increased expression of MHC isoforms in cardiac muscle |
| B. | increased catecholamine plasma levels |
| C. | increased number of receptors |
| D. | increased affinity of receptors |
| E. | vasodilation of peripheral vessels |
| Answer» C. increased number of receptors | |
| 339. |
Signs and effects of hyperparathyroidism include all EXCEPT: |
| A. | renal stones |
| B. | demineralization of bones |
| C. | Chvostek s and Trousseau s signs |
| D. | hypercalcaemia |
| E. | hypophosphataemia |
| Answer» D. hypercalcaemia | |
| 340. |
Regarding atrial natriuretic peptide, which statement is INCORRECT? |
| A. | cardiac innervation is not required for secretion to occur |
| B. | its action is terminated by receptor-mediated endocytosis |
| C. | its filtration fraction is decreased |
| D. | it is secreted by heart, lung and brain |
| E. | glucocorticoids increase its secretion |
| Answer» D. it is secreted by heart, lung and brain | |
| 341. |
Regarding noradrenergic stimulation: |
| A. | miosis occurs |
| B. | increases blood flow to the skin |
| C. | increases thresholds in the reticular formation |
| D. | causes erection in males |
| E. | elevates free fatty acid levels |
| Answer» E. elevates free fatty acid levels | |
| 342. |
Which decreases Na+ -K+ -ATPase pump activity? |
| A. | thyroid hormones |
| B. | dopamine |
| C. | G-actin |
| D. | intracellular sodium |
| E. | insulin |
| Answer» C. G-actin | |
| 343. |
Regarding red blood cells, all are true EXCEPT: |
| A. | erythropoiesis is stimulated by anaemia and hypoxia |
| B. | after splenectomy, malaria has a higher mortality |
| C. | normal adult haemoglobin is designated 2 2 |
| D. | about 5% of adult haemoglobin is haemoglobin A2 ( 2 2) |
| E. | G6PD deficiency increases red cell susceptibility to lysis by drugs and infection |
| Answer» E. G6PD deficiency increases red cell susceptibility to lysis by drugs and infection | |
| 344. |
Regarding cholinergic stimulation: |
| A. | causes amylase secretion from salivary glands |
| B. | decreases secretion from pancreatic ????? |
| C. | relaxes the gallbladder |
| D. | has no effect on renal arterioles |
| E. | relaxes bronchial smooth muscle |
| Answer» E. relaxes bronchial smooth muscle | |
| 345. |
Which volume of distribution is evaluated with which substance? |
| A. | plasma D2O |
| B. | RBC volume 51Cr |
| C. | ECF Evans Blue |
| D. | Interstitial fluid Inulin |
| E. | ICF mannitol |
| Answer» C. ECF Evans Blue | |
| 346. |
As a percentage of total blood volume, which of the following values are CORRECT? |
| A. | 40% is in the pulmonary circulation |
| B. | 13% is in the systemic arteries |
| C. | 20% is in the systemic arterioles and capillaries |
| D. | 30% is in the veins |
| E. | none of the above are correct |
| Answer» C. 20% is in the systemic arterioles and capillaries | |
| 347. |
Herring bodies are: |
| A. | nuclei of the hypothalamus |
| B. | secretory granules in the posterior pituitary |
| C. | circumventricular organs |
| D. | neurons connecting vestibular nuclei with the vomiting centre |
| E. | vesicles containing ACTH, TSH, GH, FSH, CH and PRL |
| Answer» D. neurons connecting vestibular nuclei with the vomiting centre | |
| 348. |
Which pattern of laboratory findings in the tale below is most consistent with a diagnosis of diabetes insipidis? 24 Hr Urine Volume Ketones Glucose Protein |
| A. | 4.0 + 0 0 |
| B. | 6.2 2+ 4+ 0 |
| C. | 1.6 0 0 4+ |
| D. | 6.4 0 0 0 |
| E. | 5.0 0 0 3+ |
| Answer» E. 5.0 0 0 3+ | |
| 349. |
Which statement regarding hyperbaric oxygen therapy is INCORRECT? |
| A. | males eliminate carboxy haemoglobin faster than females |
| B. | gas around the body is normal air compressed to the same high pressure |
| C. | it produces marked increases in dissolved oxygen in the blood |
| D. | oxygen is administered at up to 3 atmospheres pressure |
| E. | toxicity includes optic neuritis |
| Answer» B. gas around the body is normal air compressed to the same high pressure | |
| 350. |
Regarding H+ renal excretion: |
| A. | the distal convoluted tubule brush border contains carbonic anhydrase |
| B. | H+ secretion occurs in all segments of the nephrons |
| C. | H+ + NH3 NH4+ is the most significant tubular buffering reaction |
| D. | CO2 is recycled / resorbed in the PCT to allow enhanced acid secretion |
| E. | collecting duct |
| Answer» E. collecting duct | |