MCQOPTIONS
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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.
| 101. |
Glycogenolysis: |
| A. | is a process of formation of glycogen in the cell |
| B. | is a process of breakdown of glycogen to reform glucose |
| C. | is the conversion of glucose into fructose |
| D. | is the process of breakdown of galactose |
| E. | is the formation of galactose from fructose |
| Answer» C. is the conversion of glucose into fructose | |
| 102. |
Regarding ATP: |
| A. | ATP is a combination of adenine, ribose and 3 phosphate radicals |
| B. | ATP are present everywhere in the cytoplasm and nucleoplasm |
| C. | ATP is otherwise called the energy currency of the body |
| D. | ATP becomes GTP after the loss of one phosphate radical |
| E. | ATP is a labile chemical compound that is present in all cells |
| Answer» E. ATP is a labile chemical compound that is present in all cells | |
| 103. |
In the body, metabolism of 10gm protein would produce approximately: |
| A. | 1 Kcal |
| B. | 41 Kcal |
| C. | 410 Kcal |
| D. | 4100 Kcal |
| E. | 41 Cal |
| Answer» C. 410 Kcal | |
| 104. |
Regarding 1,25 dihydroxycholecalciferol (calcitriol): |
| A. | it is formed by the action of sunlight on pre vitamin D3 |
| B. | it exerts its action via stimulation of adenylcyclase |
| C. | it decreases calcium reabsorption from kidneys |
| D. | its formation is increased with elevated plasma Ca++ levels |
| E. | it causes increased formation of calbindin-D proteins |
| Answer» F. | |
| 105. |
The following are active components in the peripheral circulation, EXCEPT: |
| A. | T3 |
| B. | T4 |
| C. | DIT |
| D. | RT3 |
| E. | all of the above |
| Answer» D. RT3 | |
| 106. |
Stimuli that increase renin secretion include all EXCEPT: |
| A. | hypotension |
| B. | Na+ depletion |
| C. | cardiac failure |
| D. | lying down |
| E. | diuretics |
| Answer» E. diuretics | |
| 107. |
Calitriol (1,25-dihydroxycholecalciferol) |
| A. | inhibits Ca++ absorption from the gut |
| B. | is formed in the proximal renal tubules from a less active precursor |
| C. | levels rise in response to increase serum PO4 levels |
| D. | inhibits osteoclasts function |
| E. | inhibits osteoblasts function |
| Answer» C. levels rise in response to increase serum PO4 levels | |
| 108. |
Which of the following reduce insulin secretion? |
| A. | acetylcholine |
| B. | GIP |
| C. | glucagon |
| D. | adrenaline |
| E. | ketoacids |
| Answer» E. ketoacids | |
| 109. |
The renal threshold for glucose, the arterial blood level at which glycosuria appears, is approximately: |
| A. | 1.8g/dL |
| B. | 180mg/dL |
| C. | 18mg/dL |
| D. | 80mg/dL |
| E. | 800mg/dL |
| Answer» C. 18mg/dL | |
| 110. |
In relation to acid base balance in the body: |
| A. | respiratory compensation in metabolic alkalosis is limited by carotid and aortic chemoreceptor response |
| B. | HCO3 concentration will decrease in compensated respiratory acidosis |
| C. | the rate of renal H+ secretion is not affected by PCO2 in respiratory acidosis |
| D. | chloride excretion is decreased in respiratory acidosis |
| E. | hepatic glutamine synthesis is decreased in chronic metabolic acidosis |
| Answer» B. HCO3 concentration will decrease in compensated respiratory acidosis | |
| 111. |
Which of the following lipoproteins is SMALLEST in size? |
| A. | chylomicrons |
| B. | very low density lipoproteins |
| C. | intermediate density lipoproteins |
| D. | low density lipoproteins |
| E. | high density lipoproteins |
| Answer» F. | |
| 112. |
Which of the following amino acids are glucogenic (ie give rise to compounds readily converted to glucose)? |
| A. | alanine |
| B. | leucine |
| C. | isoleucine |
| D. | phenylalanine |
| E. | tyrosine |
| Answer» B. leucine | |
| 113. |
Regarding brown fat, which of the following is TRUE? |
| A. | it is fat with a large percentage of melatonin as a constituent |
| B. | it has extensive parasympathetic innervation |
| C. | it is more abundant in adults than in infants |
| D. | heat production is assisted by uncoupling of the H+ /ATP generator system in mitochondria |
| E. | brown fat cells contain multiple droplets of fat |
| Answer» B. it has extensive parasympathetic innervation | |
| 114. |
Regarding the basal metabolic rate, which of the following is TRUE? |
| A. | it is measured in the absence of disease, at room temperature, within 12 hours of a meal with a Benedict apparatus and the subject asleep |
| B. | it increases 24% per degree Celsius of body temperature above 37 |
| C. | it is decreased during the latter stage of starvation, explaining the initial rapid weight loss than a slowing down of weight loss |
| D. | it declines in pregnancy |
| E. | it correlates closer to weight than to body surface area |
| Answer» D. it declines in pregnancy | |
| 115. |
Regarding thyroid hormones, which statement is INCORRECT? |
| A. | thyroid hormones bind to receptors in cell nuclei |
| B. | T3 is less potent than T4 |
| C. | thyroid hormones increase O2 consumption |
| D. | T3 promotes nitrogen excretion |
| E. | cerebral glucose consumption is increased by thyroid hormones |
| Answer» C. thyroid hormones increase O2 consumption | |
| 116. |
Biological energy can be derived from all EXCEPT: |
| A. | lactic acid |
| B. | phosphorylcreatine |
| C. | guanosine triphosphate |
| D. | co enzyme A |
| E. | urea |
| Answer» F. | |
| 117. |
Regarding thyroxine, which of the following is INCORRECT? |
| A. | increases number of adrenergic receptors on the heart |
| B. | there is a preferential expression of myosin in the muscle fibres of the heart in the presence of thyroxine |
| C. | thyroid hormones decrease carbohydrate absorption by the stomach and small bowel |
| D. | hyaluronic acid accumulates in the skin if there is a deficiency of thyroxine |
| E. | large doses can increase body temperature |
| Answer» D. hyaluronic acid accumulates in the skin if there is a deficiency of thyroxine | |
| 118. |
Regarding the respiratory quotient, which of the following is TRUE? |
| A. | it is the ratio of CO2 produced to the volume of O2 consumed per unit of time |
| B. | is related to tidal volume |
| C. | is inversely proportioned to pO2 |
| D. | has a value of 2.3 for fats |
| E. | varies with age |
| Answer» B. is related to tidal volume | |
| 119. |
Which of the following is NOT an unsaturated fatty acid? |
| A. | oleic acid |
| B. | arachidonic acid |
| C. | linoleic acid |
| D. | linolenic acid |
| E. | stearic acid |
| Answer» F. | |
| 120. |
Regarding protein metabolism in starvation, which statement is INCORRECT? |
| A. | glucose has a protein sparing effect by increasing insulin secretion |
| B. | death occurs when protein depletion reaches 50% of normal level |
| C. | total starvation leads to loss of up to 5gms/day of urea nitrogen due to protein catabolism |
| D. | most protein catabolised comes from the liver, spleen and skeletal muscles |
| E. | rapid protein depletion is the terminal phase once fat stores have been almost totally catabolised |
| Answer» D. most protein catabolised comes from the liver, spleen and skeletal muscles | |
| 121. |
Regarding carbohydrate metabolism in starvation, which statement is INCORRECT? |
| A. | hepatic glycogenolysis precedes skeletal muscle glycogenolysis |
| B. | blood glucose falls less in women due to greater fat stores |
| C. | glycogen stores are exhausted after half to one day |
| D. | blood glucose level is maintained above a level that would produce symptomatic hypoglycaemia |
| E. | skeletal muscle contains about four times as much glycogen as the liver |
| Answer» C. glycogen stores are exhausted after half to one day | |
| 122. |
Regarding brown fat, which statement is INCORRECT? |
| A. | fat cells have extensive parasympathetic innervation |
| B. | responsible for part of the post-prandial heat production |
| C. | fat cells contain several droplets of fat |
| D. | prominent between and around the scapulae of infants |
| E. | fat cells contain many mitochondria |
| Answer» B. responsible for part of the post-prandial heat production | |
| 123. |
Regarding lipoproteins, which statement is INCORRECT? |
| A. | VLDL transport cholesterol formed in liver to extrahepatic tissues |
| B. | chylomicrons can cause post-prandial plasma to appear milky |
| C. | LDL are taken up by macrophages |
| D. | oestrogens increase plasma HDL levels |
| E. | elevated IDL levels predispose to atherosclerosis |
| Answer» B. chylomicrons can cause post-prandial plasma to appear milky | |
| 124. |
Which of the following does NOT increase the activity of intracellular hormonesensitive lipase? |
| A. | GH |
| B. | PGE |
| C. | thyroxine |
| D. | glucagon |
| E. | cortisol |
| Answer» C. thyroxine | |
| 125. |
Which of the following causes a positive nitrogen balance? |
| A. | increased cortisol secretion |
| B. | starvation |
| C. | decreased insulin secretion |
| D. | forced immobilisation |
| E. | increased testosterone secretion |
| Answer» F. | |
| 126. |
Regarding uric acid, which statement is INCORRECT? |
| A. | the majority of filtered uric acid is reabsorbed in the proximal tubule |
| B. | xanthine oxidase catalyses its synthesis |
| C. | may be elevated in leukaemia and pre-eclampsia |
| D. | does not undergo renal tubular secretion |
| E. | its excretion rate can be halved by changing to a purine-free diet |
| Answer» E. its excretion rate can be halved by changing to a purine-free diet | |
| 127. |
Nucleotide breakdown releases purines and pyrimidines. Which of the following is NOT their subsequent fate? |
| A. | re-used to form nucleosides, nucleotides and nucleic acids |
| B. | excreted unchanged in urine |
| C. | directly enter the urea cycle |
| D. | pyrimidines are catabolised to carbon dioxide and ammonia |
| E. | purines are catabolised to uric acid |
| Answer» D. pyrimidines are catabolised to carbon dioxide and ammonia | |
| 128. |
Regarding ketone bodies, which statement is INCORRECT? |
| A. | formed following ingestion of a high fat/low carbohydrate diet |
| B. | acetoacetate and beta-hydroxybutyrate formation leads to a metabolic acidosis |
| C. | acetone is excreted in the urine |
| D. | readily metabolised by the liver |
| E. | acetone formation leads to ketotic breath |
| Answer» E. acetone formation leads to ketotic breath | |
| 129. |
Which statement regarding lipoprotein lipase is INCORRECT? |
| A. | it is not hormone sensitive |
| B. | it requires heparin as a co-factor |
| C. | it is confined to adipose tissue |
| D. | its activity is decreased by stress |
| E. | it clears chylomicrons and VLDL from circulation by degradation of triglyceride |
| Answer» D. its activity is decreased by stress | |
| 130. |
All of the following, except one, inhibit insulin secretion. Which is it? |
| A. | somatostatin |
| B. | thiazide diuretics |
| C. | propranolol |
| D. | insulin |
| Answer» F. | |
| 131. |
Steroid hormones: |
| A. | open ion channels in cell membrane |
| B. | act via cytoplasmic or nuclear receptors |
| C. | increase intracellular cAMP |
| D. | increase tyrosine kinase activity of transmembrane receptors |
| E. | act via a serpentine receptor |
| Answer» C. increase intracellular cAMP | |
| 132. |
Human hepatic bile (hepatic bile duct) is largely: |
| A. | water |
| B. | bile salts |
| C. | bile pigment |
| D. | cholesterol |
| E. | lecithin |
| Answer» B. bile salts | |
| 133. |
The nutritionally essential amino acids include: |
| A. | alanine |
| B. | cysteine |
| C. | tyrosine |
| D. | methionine |
| E. | glutamine |
| Answer» E. glutamine | |
| 134. |
The largest glycogen store in the adult body is in the: |
| A. | liver |
| B. | spleen |
| C. | muscle |
| D. | pancreas |
| E. | circulating red cell mass |
| Answer» D. pancreas | |
| 135. |
The most common cell type of the endocrine pancreas is: |
| A. | A cells |
| B. | B cells |
| C. | C cells |
| D. | D cells |
| E. | F cells |
| Answer» C. C cells | |
| 136. |
GLUT is an example of: |
| A. | simple diffusion |
| B. | facilitated diffusion |
| C. | primary active transport |
| D. | secondary active transport |
| E. | endocytosis |
| Answer» C. primary active transport | |
| 137. |
Thyroxine (T4) has greater affinity for: |
| A. | thyroxine-binding globulin |
| B. | transthyretin |
| C. | thyroxine-binding pre-albumin |
| D. | albumin |
| E. | triiodothyronine |
| Answer» B. transthyretin | |
| 138. |
TSH secretion is stimulated by: |
| A. | dopamine |
| B. | somatostatin |
| C. | cold temperatures |
| D. | stress |
| E. | glucocorticoids |
| Answer» D. stress | |
| 139. |
Regarding aldosterone: |
| A. | it is released in response to hypokalaemia |
| B. | it has glucocorticoid action |
| C. | it works via G proteins to increase Na+ reabsorption |
| D. | its release results in alkaline urine |
| E. | it is highly protein-bound |
| Answer» C. it works via G proteins to increase Na+ reabsorption | |
| 140. |
Aldosterone is secreted by: |
| A. | zona reticularis |
| B. | zona fasciculata |
| C. | zona glomerulosa |
| D. | zona fasciculata and reticularis |
| E. | zona glomerulosa and fasciculata |
| Answer» D. zona fasciculata and reticularis | |
| 141. |
Calcitonin secretion is increased by: |
| A. | gastrin |
| B. | CCK |
| C. | secretin |
| D. | glucagon |
| E. | all of the above |
| Answer» F. | |
| 142. |
All of the following bind to intracellular receptors EXCEPT: |
| A. | cortisol |
| B. | aldosterone |
| C. | 1,25-DHCC |
| D. | parathyroid hormone |
| E. | thyroxine |
| Answer» E. thyroxine | |
| 143. |
Insulin release: |
| A. | is inhibited by raised cyclic AMP in pancreatic cells |
| B. | is not stimulated by blood glucose levels below 6mmol/l |
| C. | is increased by adrenergic stimulators |
| D. | is inhibited by phosphor diesterase inhibitors |
| E. | is increased by somatostatin |
| Answer» D. is inhibited by phosphor diesterase inhibitors | |
| 144. |
Both insulin and somatostatin: |
| A. | are released from extra-pancreatic sites |
| B. | receptors are linked to G proteins |
| C. | inhibit release of glucagon |
| D. | cause K+ uptake by cells |
| E. | are polypeptides containing two chains linked by disulphide bonds |
| Answer» D. cause K+ uptake by cells | |
| 145. |
How many trophic hormones does the anterior pituitary produce? |
| A. | 2 |
| B. | 3 |
| C. | 5 |
| D. | 6 |
| E. | 8 |
| Answer» D. 6 | |
| 146. |
The approximate ratio of fat : CHO energy stores is: |
| A. | 2 : 1 |
| B. | 4 : 1 |
| C. | 10 : 1 |
| D. | 20 : 1 |
| E. | 40 : 1 |
| Answer» F. | |
| 147. |
Under aerobic conditions, 1mol glucose forms: |
| A. | 2mol ATP |
| B. | 8mol ATP |
| C. | 16mol ATP |
| D. | 38mol ATP |
| E. | 42mol ATP |
| Answer» E. 42mol ATP | |
| 148. |
All of the following are high energy phosphate compounds EXCEPT: |
| A. | adenosine triphosphate |
| B. | glucose 6-phosphate |
| C. | creatine phosphate |
| D. | adenosine diphosphate |
| E. | guanosine triphosphate |
| Answer» C. creatine phosphate | |
| 149. |
With regard to water excretion: |
| A. | 280 l is filtered per day |
| B. | it is impossible to excrete more than 23 l/day |
| C. | most regulation is via manipulation of the gradients along the loop of Henle |
| D. | vasopressin acts to insert water channels into the basolateral cell membrane of the collecting ducts |
| E. | water reabsorption in the collecting ducts can alter by a factor of 2.5 dependent on the presence of vasopressin |
| Answer» F. | |
| 150. |
Nutritionally essential amino acids include: |
| A. | glycine |
| B. | serine |
| C. | lysine |
| D. | glutamine |
| E. | tyrosine |
| Answer» D. glutamine | |