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.
| 201. |
Regarding bilirubin: |
| A. | unconjugated bilirubin is more soluble than conjugated |
| B. | all conjugated bilirubin is excreted via the intestine |
| C. | bile duct obstruction causes jaundice secondary to unconjugated hyperbilirubinaemia |
| D. | haemolytic anaemia may cause ?????? hyperbilirubinaemia |
| Answer» E. | |
| 202. |
Which form of intestinal smooth muscle contraction does NOT occur in normal health? |
| A. | peristalsis |
| B. | weak antiperistalsis |
| C. | peristaltic rushes |
| D. | tonic contractions |
| Answer» D. tonic contractions | |
| 203. |
In the adrenal cortex: |
| A. | the zona glomerulosa has 17 alpha-hydroxylase and no aldosterone synthase |
| B. | all the cholesterol is synthesised from acetate |
| C. | zona fasciculata makes up 10% of the mass of the adrenal gland |
| D. | angiotensin II binds to receptors in the zona reticularis |
| Answer» F. | |
| 204. |
Regarding the islets of Langerhans: |
| A. | D cells secrete pancreatic polypeptide |
| B. | A cells are the most common |
| C. | they are most plentiful in the body of the pancreas |
| D. | blood from the islets drain into the hepatic portal vein |
| Answer» E. | |
| 205. |
Thyroid hormones increase the oxygen consumption of: |
| A. | lymph nodes |
| B. | spleen |
| C. | brain |
| D. | anterior pituitary gland |
| Answer» F. | |
| 206. |
Regarding protein metabolism, which statement is CORRECT? |
| A. | increases the respiratory quotient to values > 1.0 |
| B. | has a specific dynamic action (SDA) of approximately 10% |
| C. | endogenous protein breakdown is inhibited by glucagon |
| D. | creatinine excretion is not depressed in starvation |
| Answer» E. | |
| 207. |
Which factor stimulates insulin secretion? |
| A. | thiazide diuretics |
| B. | phenytoin |
| C. | theophylline |
| D. | blockers |
| Answer» D. blockers | |
| 208. |
The action of gastrin includes all EXCEPT: |
| A. | stimulation of insulin secretion after a carbohydrate meal |
| B. | stimulation of gastric acid secretion |
| C. | stimulation of gastric motility |
| D. | contraction of gastro-oesophageal junction musculature |
| Answer» B. stimulation of gastric acid secretion | |
| 209. |
Regarding carbon dioxide transport in blood, which statement is INCORRECT? |
| A. | oxygen is about 20 times less soluble in blood |
| B. | deoxygenation of blood increase its ability to carry carbon dioxide |
| C. | arterial blood transports about 20% in dissolved form |
| D. | venous blood has higher haematocrit than arterial blood |
| E. | carbamino compounds are formed by reaction with both plasma proteins and Hb |
| Answer» D. venous blood has higher haematocrit than arterial blood | |
| 210. |
Fanconi s syndrome of decreased levels of ATP in the tubular epithelium of the PCT: |
| A. | decreases Na+ extrusion from the cell into the interstitium |
| B. | causes increased phosphate absorption |
| C. | causes metabolic alkalosis |
| D. | results in decreased amino acid excretion |
| E. | collecting duct |
| Answer» B. causes increased phosphate absorption | |
| 211. |
Regarding free fatty acids in plasma, which of the following is NOT true? |
| A. | they account for less than 10% of total fatty acids in plasma |
| B. | they are complexed with a protein carrier |
| C. | they can be metabolised to CO2 and water in skeletal and cardiac muscle |
| D. | their level in plasma decreases as plasma adrenaline increases |
| E. | they are converted to energy by the citric acid cycle |
| Answer» E. they are converted to energy by the citric acid cycle | |
| 212. |
Uric acid handling by the kidneys involves: |
| A. | filtration only |
| B. | secretion by tubules only |
| C. | filtration and secretion |
| D. | filtration and reabsorption |
| E. | filtration, reabsorption and secretion |
| Answer» F. | |
| 213. |
Regarding serotonin: |
| A. | the highest concentration is in the brain |
| B. | formed by hydroxylation and decarboxylation of tyrosine |
| C. | catabolised by COMT |
| D. | some receptors are ion channels |
| E. | mediates smooth muscle relaxation |
| Answer» E. mediates smooth muscle relaxation | |
| 214. |
All but which of the following cause contraction of the mesengial cells? |
| A. | endothelins |
| B. | angiotensin II |
| C. | ADH |
| D. | noradrenaline |
| E. | cAMP |
| Answer» F. | |
| 215. |
Serotonin is noted in all but: |
| A. | sexual behaviour |
| B. | obesity |
| C. | platelet aggregation |
| D. | mood |
| E. | vomiting |
| Answer» B. obesity | |
| 216. |
All but which of the following are involved in the movement of Na+/Cl- across the apical membrane of the proximal tubules? |
| A. | Na+ / 2Cl- / K+ co-transporter (CT) |
| B. | Na+/ glucose CT |
| C. | Na+/P??? CT |
| D. | Cl- / base exchanges |
| E. | Na+ / H+ exchanges |
| Answer» B. Na+/ glucose CT | |
| 217. |
Which of the following substances would NOT cause contraction of mesangial cells? |
| A. | angiotensin II |
| B. | dopamine |
| C. | vasopressin |
| D. | histamine |
| E. | platelet activating factor |
| Answer» C. vasopressin | |
| 218. |
Which of the following will cause an increase in GFR? |
| A. | dehydration |
| B. | ureteral obstruction |
| C. | afferent arteriole constriction |
| D. | hypoproteinaemia |
| Answer» E. | |
| 219. |
Which statement regarding parathyroid hormone (PTH) is INCORRECT? |
| A. | it is continuously secreted by the parathyroid glands |
| B. | it is synthesised and secreted by the oxyntic cells |
| C. | it is rapidly cleaved in the Kupffer cells of the liver |
| D. | it increases osteoclasts activity in bone |
| E. | it increases formation of 1,25-dihydroxycholecalciferol |
| Answer» C. it is rapidly cleaved in the Kupffer cells of the liver | |
| 220. |
Cardiac muscle fibres: |
| A. | develop tetany only at very high stimulation frequencies |
| B. | develop less tension when stretched due to decreased actin-myosin overlap |
| C. | can derive only 5% of basal caloric requirement from fat |
| D. | have a T-system located at the A-I junctions |
| E. | remain absolutely refractory until the membrane potential repolarises to - 50mV |
| Answer» F. | |
| 221. |
Which statement is TRUE regarding cardiac muscle? |
| A. | cardiac muscle fibres are multinucleated |
| B. | they are smaller than skeletal muscle fibres |
| C. | Ca2+ release is triggered by membrane repolarisation |
| D. | the elastic Titin protein component is greater than in skeletal muscle, adding stiffness |
| E. | the amount of Ca2+ in the sarcoplasmic reticulum is decreased by catecholamine stimulation |
| Answer» C. Ca2+ release is triggered by membrane repolarisation | |
| 222. |
For cardiac muscle, which is FALSE? |
| A. | HERG really is the acronym for human ether-a-go-go related gene |
| B. | intercolated discs are calcified structures within cardiac muscle cells |
| C. | resting membrane potential is -90mV |
| D. | cardiac muscle requires continuous supply of O2 to function |
| E. | cardiac muscle action potential time decreases with increasing heart rate |
| Answer» C. resting membrane potential is -90mV | |
| 223. |
Regarding cardiac muscle, which statement is INCORRECT? |
| A. | resting membrane potential is about -90mV |
| B. | energy source at rest is mainly fat |
| C. | mechanical response lasts about twice as long as electrical response |
| D. | tetanus cannot occur |
| E. | it has an all-or-nothing contractile response |
| Answer» D. tetanus cannot occur | |
| 224. |
Regarding the structure of cardiac muscle, which statement is INCORRECT? |
| A. | T-system lies at Z-lines |
| B. | functions as a syncytium due to the presence of tight junctions |
| C. | intercalated discs occur at Z-lines |
| D. | contains large numbers of elongated mitochondria |
| E. | thin filaments include troponin T, C and I |
| Answer» C. intercalated discs occur at Z-lines | |
| 225. |
Which of the following does NOT increase plasma calcium? |
| A. | parathyroid hormone |
| B. | vitamin D |
| C. | growth hormone |
| D. | thyroxine |
| E. | calcitonin |
| Answer» F. | |
| 226. |
Regarding the cardiac muscle action potential, which statement is INCORRECT? |
| A. | sodium ions enter via fast channels in phase 0 |
| B. | chloride ions may enter cell during phase 1 |
| C. | sodium ions enter via slow channels in phase 2 |
| D. | relative refractory period ends in phase 3 |
| E. | class I anti-arrhythmics reduce the slope of phase 4 |
| Answer» B. chloride ions may enter cell during phase 1 | |
| 227. |
Stimuli that increase aldosterone secretion and do not effect glucocorticoid secretion includes all EXCEPT: |
| A. | low Na+ intake |
| B. | high K+ intake |
| C. | standing |
| D. | secondary hyperaldosteronism |
| E. | haemorrhage |
| Answer» F. | |
| 228. |
Which of the following does NOT increase secretion of glucagon? |
| A. | diabetes mellitus |
| B. | adrenoceptor agonists |
| C. | GABA |
| D. | starvation |
| E. | exercise |
| Answer» D. starvation | |
| 229. |
Regarding extracellular volume maintenance: |
| A. | control of sodium balance is the major mechanism maintaining ECF volume |
| B. | a rise in ECF volume stimulates vasopressin secretion |
| C. | osmotic stimuli over-ride volume stimuli in the regulation of vasopressin secretion |
| D. | vasopressin causes Na+ retention by the kidney |
| E. | angiotensin II inhibits aldosterone secretion |
| Answer» B. a rise in ECF volume stimulates vasopressin secretion | |
| 230. |
Opioid peptides: |
| A. | are not formed from precursors |
| B. | include morphine as an example |
| C. | form the opioid receptors in the brain |
| D. | are mainly found in the brain and gastrointestinal tract |
| E. | are almost always excreted unchanged |
| Answer» E. are almost always excreted unchanged | |
| 231. |
A decrease in extracellular K+: |
| A. | makes the resting membrane more negative in nerve cells |
| B. | causes a similar effect in nerve cells as a decrease in extracellular Na+ |
| C. | has little effect in nerve cell membrane potential |
| D. | may decrease nerve cell action potential size |
| E. | cause a similar effect in nerve cells as an increase in extracellular Ca++ |
| Answer» F. | |
| 232. |
Which of the following does NOT increase aldosterone secretion? |
| A. | constriction of the IVC in the thorax |
| B. | ACTH |
| C. | surgery |
| D. | hyperkalaemia |
| E. | lying supine from the standing position |
| Answer» F. | |
| 233. |
Which of the following do NOT increase TSH secretion? |
| A. | TRH |
| B. | glucocorticoids |
| C. | infants exposed to cold temperature |
| D. | acute psychosis |
| E. | night time |
| Answer» C. infants exposed to cold temperature | |
| 234. |
Which of the following does NOT increase parathyroid hormone secretion? |
| A. | high plasma magnesium |
| B. | low plasma calcium |
| C. | high plasma phosphate |
| D. | -adrenergic discharge |
| E. | cyclic AMP |
| Answer» B. low plasma calcium | |
| 235. |
Which of the following does NOT increase secretion of atrial natriuretic peptide? |
| A. | -adrenoceptor agonists |
| B. | immersion in water up to the neck |
| C. | exercise |
| D. | endothelin |
| E. | changing from erect position to supine |
| Answer» B. immersion in water up to the neck | |
| 236. |
Which of the following is NOT associated with an increase in erythropoietin secretion? |
| A. | aminophylline |
| B. | renal cell carcinoma |
| C. | cobalt salts |
| D. | thyroxine |
| E. | adenosine |
| Answer» B. renal cell carcinoma | |
| 237. |
All of the following increase renin secretion EXCEPT: |
| A. | sodium depletion |
| B. | diuretics |
| C. | hypertension |
| D. | cardiac failure |
| E. | cirrhosis |
| Answer» D. cardiac failure | |
| 238. |
Which of the following does NOT inhibit secretion of glucagon? |
| A. | ketones |
| B. | adrenoceptor agonists |
| C. | secretin |
| D. | amino acids |
| E. | somatostatin |
| Answer» E. somatostatin | |
| 239. |
Which of the following does NOT increase intestinal calcium absorption? |
| A. | hypocalcaemia |
| B. | parathyroid hormone (PTH) |
| C. | glucocorticoids |
| D. | hypervitaminosis D |
| E. | protein in diet |
| Answer» D. hypervitaminosis D | |
| 240. |
Which of the following does NOT inhibit insulin secretion? |
| A. | somatostatin |
| B. | atropine |
| C. | propranolol |
| D. | gastrin |
| E. | phenytoin |
| Answer» E. phenytoin | |
| 241. |
Which of the following does NOT decrease intestinal calcium absorption? |
| A. | hypercalcaemia |
| B. | decreased PTH |
| C. | hypovitaminosis D |
| D. | growth hormone |
| E. | phytic acid and oxalate in intestine |
| Answer» E. phytic acid and oxalate in intestine | |
| 242. |
The content of chylomicrons includes: |
| A. | aproprotein E and aproprotein A |
| B. | cholesterol 30%, protein 20%, triglyceride 50% |
| C. | lethicin 10%, cholesterol 25%, triglyceride 65% |
| D. | protein 2%, cholesterol 5%, triglyceride 90% |
| E. | the enzyme protein phospholipase |
| Answer» E. the enzyme protein phospholipase | |
| 243. |
Regarding the intracellular fluid, which is NOT CORRECT? |
| A. | it accounts for 40% of body weight |
| B. | its volume can be estimated using radio-active inulin |
| C. | it contains more protein (in mg/L water) than extracellular fluid |
| D. | the composition of intracellular fluid varies with the nature and function of the cell |
| E. | all of the above are true |
| Answer» C. it contains more protein (in mg/L water) than extracellular fluid | |
| 244. |
Regarding the insulin receptor, which statement is INCORRECT? |
| A. | it is present even in cells which do not increase their glucose intake in response to insulin |
| B. | insulin binds to the subunit on the outer surface of the cell membrane |
| C. | it is a tetramer of two and two subunits |
| D. | the binding of insulin decreases the activity of tyrosine kinase on the intracellular end of the receptor |
| E. | the complex of insulin and receptor become internalised by the cell |
| Answer» C. it is a tetramer of two and two subunits | |
| 245. |
Which statement regarding the thyroid gland and its hormones is INCORRECT? |
| A. | thyroid hyperactivity is associated with an increase in plasma catecholamines |
| B. | iodide trapping by thyroid cells is an active process |
| C. | thyroid hormones enter cells by diffusion across the cell membrane |
| D. | thyroid hormones cause an increase in 2,3 - DPG |
| E. | thyroid hormones increase growth hormone secretion |
| Answer» B. iodide trapping by thyroid cells is an active process | |
| 246. |
The opioid receptor is involved in: |
| A. | analgesia |
| B. | respiratory depression |
| C. | miosis |
| D. | dependence |
| E. | all of the above |
| Answer» B. respiratory depression | |
| 247. |
In which state is extracellular buffering more important than intracellular? |
| A. | respiratory acidosis |
| B. | respiratory alkalosis |
| C. | metabolic acidosis |
| D. | metabolic alkalosis |
| E. | collecting duct |
| Answer» E. collecting duct | |
| 248. |
Which substance relaxes mesangial cells? |
| A. | angiotensin II |
| B. | ADH |
| C. | noradrenaline |
| D. | thromboxane A2 |
| E. | ANP |
| Answer» F. | |
| 249. |
With regard to the effect of thyroid hormone on the cardiovascular system, which of the following are TRUE? |
| A. | level of noradrenaline are increased |
| B. | adrenergic receptor affinity is decreased in heart muscle |
| C. | circulating adrenaline levels are decreased |
| D. | thyroid hormone levels alter the ratio of cardiac myosin isoform types |
| E. | none of the above |
| Answer» E. none of the above | |
| 250. |
Regarding the iodide pump in thyroid cells, which is NOT true? |
| A. | it is stimulated by TSH |
| B. | it depends on Na+ / K+ ATPase activity |
| C. | it pumps iodide into the colloid, after entering the cell down an electrical gradient |
| D. | it pumps iodide against an electrical gradient |
| E. | its activity can be measured with trace doses of radioactive iodine |
| Answer» D. it pumps iodide against an electrical gradient | |