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Question 1
Correct
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Which of the following refers to the process of decoding messenger RNA into an amino acid sequence?
Your Answer: Translation
Explanation:Messenger RNA (mRNA) is decoded in a ribosome, outside the nucleus, to produce a specific amino acid chain, or polypeptide. This is known as translation and follows after the process transcription of DNA to RNA in the cell’s nucleus.
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This question is part of the following fields:
- Medicine
- Metabolism
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Question 2
Correct
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Drug-induced lupus erythematosus most often occurs after taking which of the following drugs?
Your Answer: Procainamide
Explanation:Many drugs are responsible for causing drug induced lupus. However, it is most commonly associated with hydralazine, procainamide and quinidine.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 3
Correct
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A 60-year-old patient diagnosed with Type-2 diabetes mellitus is not responding to dietary modifications and weight reduction. He needs to be started on an oral hypoglycaemic agent. Which among the following statements regarding oral hypoglycaemic agents is true?
Your Answer: Acarbose inhibits α-glucosidase
Explanation:Different Oral Hypoglycaemic Agents (OHAs) and their respective mechanism(s) of action include:• Sulfonylureas (such as, glipizide, gliclazide, glimepiride) – bind to ATP sensitive Potassium channels (K – ATP channels) in the 𝝱 cells of the islets of the pancreas. Inhibition of these channels lead to an altered resting membrane potential in these cells causing an influx of calcium which increases insulin secretion.• Meglitinides (like Repaglinide) through a different receptor, they similarly regulate K – ATP channels thereby causing an increase in insulin secretion.• Biguanides (e.g., Metformin) increase the hepatic AMP-activated protein kinase activity leading to reduced gluconeogenesis and lipogenesis and increased insulin-mediated uptake of glucose in muscles. (it doesn’t increase insulin secretion)• Thiazolidinediones (rosiglitazone, pioglitazone) bind to PPAR-𝝲 and increase peripheral uptake of glucose and decrease hepatic glucose production.• α-Glucosidase inhibitors (such as acarbose, miglitol, voglibose) competitively inhibit α-glucosidase enzymes in the intestine that digest the dietary starch thus, inhibiting the polysaccharide reabsorption as well as metabolism of sucrose to glucose and fructose.• DPP-4 inhibitors (sitagliptin, saxagliptin, vildagliptin, linagliptin, alogliptin) prolong the action of glucagon-like peptide. This leads to inhibition of glucagon release, increase in insulin secretion and a decrease in gastric emptying leading to a decrease in blood glucose levels.• SGLT2 inhibitors (dapagliflozin and canagliflozin) inhibit glucose reabsorption in the proximal tubules of the renal glomeruli leading to glycosuria which in-turn reduces blood glucose levels.Note: Side effects of pioglitazone are weight gain, pedal oedema, bone loss and precipitation of congestive cardiac failure.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 4
Correct
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Question 5
Correct
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Choose the most correct missing words to complete the statement: A portion of circulating growth hormone is bound to the ____ receptor and activates the ____ pathway that mediates its effect.
Your Answer: Growth hormone receptor (extracellular domain), jak 2stat
Explanation:The growth hormone receptor is a transmembrane protein involved in the STATs, MAPK and PI3-kinase/Akt pathways. The JAK-STAT signalling pathway is activated by different ligands, such as growth hormone, interferon and interleukin. This pathway is involved in the expression of genes associated with oncogenesis, immunity, proliferation, differentiation and apoptosis. Errors in these pathways can produce leukaemia’s and other myeloproliferative disorders.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 6
Correct
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Question 7
Incorrect
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Immortality can result from over expression of which enzyme?
Your Answer: None of the above
Correct Answer: Telomerase
Explanation:Telomerase activity is seen in germ cells and is absent in somatic cells. Telomeres prevent the chromosomes from shortening and prevent the coding portion of the DNA from being lost, thus allowing the cell to replicate indefinitely.
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This question is part of the following fields:
- Genetics
- Medicine
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Question 8
Correct
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To which of the following plasma proteins is T4 most bound in plasma?
Your Answer: Thyroxine-binding globulin
Explanation:Thyroxine-binding globulin, also known as TBG, is one of the three transport proteins responsible for carrying T4 and T3 through the circulatory system. It carries most of the T4 present in plasma, which it binds to strongly, shielding the hydrophobic hormones from the aqueous surroundings.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 9
Correct
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The steps of cardiac cycle in sequence are:
Your Answer: Isovolumic contraction, ejection, isovolumic relaxation, passive ventricular filling, active ventricular filling.
Explanation:The cardiac cycle refers to a complete heartbeat from its generation to the beginning of the next beat, and so includes the diastole, the systole, and the intervening pause.1st stage: diastole, or passive filling is when the semilunar valves (the pulmonary valve and the aortic valve) close, the atrioventricular (AV) valves (the mitral valve and the tricuspid valve) open, and the whole heart is relaxed. 2nd stage: atrial systole, is when the atrium contracts, and blood flows from atrium to the ventricle (active filling).3rd stage: isovolumic contraction is when the ventricles begin to contract, the AV and semilunar valves close, and there is no change in volume. 4th stage: ventricular ejection, is when the ventricles are contracting and emptying, and the semilunar valves are open. 5th stage: isovolumic relaxation time, pressure decreases, no blood enters the ventricles, the ventricles stop contracting and begin to relax, and the semilunar valves close due to the pressure of blood in the aorta.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 10
Correct
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With regards to environmental temperature, for each degree Celsius of elevation, the metabolic rate rises?
Your Answer: 0.14
Explanation:An increase in body temperature is associated with a higher metabolic rate. Evidence suggests that an increase of 1°C in your body temperature increases your metabolism by 10 to 14%.
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This question is part of the following fields:
- Medicine
- Metabolism
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Question 11
Correct
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Which of the following would be a contraindication to thrombolysis?
Your Answer: Intracranial neoplasm
Explanation:Absolute contraindications to thrombolysis include:
- Previous intracranial bleeding at any time
- Stroke in less than 6 months
- Closed head or facial trauma within 3 months
- Suspected aortic dissection
- Ischemic stroke within 3 months (except in ischemic stroke within 3 hours time)
- Active bleeding diathesis
- Uncontrolled high blood pressure (>180 systolic or >100 diastolic)
- Known structural cerebral vascular lesion
- Arterio-venous malformations
- Thrombocytopenia
- Known coagulation disorders
- Aneurysm
- Brain tumours
- Pericardial effusion
- Septic embolus
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 12
Correct
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From which of the following can niacin be synthesized in humans
Your Answer: Tryptophan
Explanation:Niacin, is also known as vitamin B3. The liver can synthesize niacin from the essential amino acid tryptophan, requiring 60 mg of tryptophan to make one mg of niacin.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 13
Incorrect
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Which factors increase the end-diastolic volume?
Your Answer: Myocardial infarction
Correct Answer: Constriction of veins
Explanation:End diastolic volume is also known as preload. It is the amount of blood the heart contracts against. Constriction of veins will decrease venous pooling and increase venous return, hence increasing the end diastolic volume. Standing will increase venous pooling hence decreasing venous return and end diastolic volume. Raised intrapericardial pressure will also decrease venous return and hence end diastolic volume.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 14
Correct
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A 22 year old nulliparous female presents with shortness of breath. She has a history of recurrent deep vein thrombosis. Complete blood count and clotting screen reveals the following results:Hb: 12.4 g/dl Plt: 137 WBC: 7.5*109/l PT: 14 secs APTT: 46 secs Which of the following would be the most likely diagnosis?
Your Answer: Antiphospholipid syndrome
Explanation:The combination of APTT and low platelets with recurrent DVTs make antiphospholipid syndrome the most likely diagnosis.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 15
Incorrect
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Which hormone is associated with the temperature surge in hot flushes?
Your Answer: Progesterone
Correct Answer: LH
Explanation:Luteinizing hormone or LH is a hormone produced by the anterior pituitary gland. Studies have shown surges in LH levels during menopausal hot flushes, suggesting that a pulsatile release of LH is responsible for increased hypothalamic norepinephrine activity, causing the hot flushes.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 16
Correct
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Question 17
Incorrect
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The nucleus tractus solitaries is medullary nucleus that processes the following inputs except:
Your Answer: Taste from the posterior 1/3 of the tongue (CN IX)
Correct Answer: Sensory input from the semi-circular canal (CN VIII)
Explanation:Located in the brain stem is a series of purely sensory nuclei known as tractus solitaries. Inputs of the nucleus tractus solitaries include:Taste information from the facial nerve (anterior 2/3 of the tongue), glossopharyngeal nerve (posterior 1/3) and vagus nerve (small area on the epiglottis).Sensory information from the ear (auricular branch of the vagus nerve).Chemoreceptors and mechanoreceptors of the general visceral afferent pathway (GVA) in the carotid body via glossopharyngeal nerve, aortic bodies, and the sinoatrial node, via the vagus nerve.Chemically and mechanically sensitive neurons of the general visceral afferent pathway (GVA) with endings located in the heart, lungs, airways, gastrointestinal system, pharynx, and liver via the glossopharyngeal and vagus nerves.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 18
Incorrect
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Which of the following are exclusively innervated by parasympathetic nerves?
Your Answer: Sweat glands
Correct Answer: Circular muscle of iris
Explanation:Circular muscle of iris is exclusively supplied by the parasympathetic nerves.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 19
Incorrect
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Dynein proteins transmit polypeptides/proteins in which direction?
Your Answer: Dynein proteins are not involved in transport
Correct Answer: From axons terminals to cell body (retrograde)
Explanation:The majority of axonal proteins are synthesised in the cell body and transported along the axons. Microtubules run along the length of the axon and provide tracks for transportation. Kinesin and Dynein are motor proteins that transport proteins and other organelles. Kinesin moves forward or anterograde transport from cell body to axon, whereas Dynein moves retrograde from axon to cell body.
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This question is part of the following fields:
- Medicine
- Neurology
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Question 20
Incorrect
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Regarding the myofilament molecules, which of the following contains binding sites for calcium that helps to initiate contraction?
Your Answer: Titin
Correct Answer: Troponin c
Explanation:Troponin T binds the troponin components to tropomyosin. Troponin I inhibits the interaction of myosin with actin and troponin C contains the binding sites for the Ca2+ that helps initiate contraction.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 21
Incorrect
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Currents caused by opening of which of the following channels contribute to the repolarization phase of the action potential of the ventricular muscle fibers?
Your Answer: Calcium channels
Correct Answer: Potassium channels
Explanation:Depolarization occurs due to opening of the voltage gated sodium channels. Repolarization occurs due to opening of the voltage gates potassium channels causing an out flux of potassium ions, decreasing the membrane potential towards resting potential.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 22
Incorrect
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Regarding oxidative deamination of amino acids, which of the following is true?
Your Answer: Leads to the formation of ribose
Correct Answer: Occurs in the kidney & liver
Explanation:Oxidative deamination is a form of deamination that generates α-keto acids and other oxidized products from amine-containing compounds, and occurs largely in the liver and kidney. Oxidative deamination is an important step in the catabolism of amino acids, generating a more metabolizable form of the amino acid, and also generating ammonia as a toxic by-product. The addition of ubiquitin to a substrate protein is called ubiquitination.
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This question is part of the following fields:
- Cell Biology
- Medicine
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Question 23
Incorrect
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Select the correct statement regarding cholecystokinin (CCK):
Your Answer: It is produced in the antrum of the stomach.
Correct Answer: It causes gallbladder contraction and pancreatic enzyme secretion.
Explanation:CCK has a primary action of increasing the motility of the gallbladder by contracting the muscles in the mucosa of the gall bladder. Apart from this, it augments the action of secretin, resulting in the production of an alkaline pancreatic juice. It increases the synthesis of enterokinase, inhibits gastric emptying and may also enhance the motility of the small intestine and colon. It is released (secreted) by your small intestine during the digestive process. It’s sometimes called pancreozymin.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 24
Incorrect
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With regard to carbohydrate absorption, which sodium-dependent glucose transporter (SGLT) is responsible for the uptake of dietary glucose from the gut?
Your Answer: SGLT 3
Correct Answer: SGLT 1
Explanation:SGLT- Sodium-dependent glucose cotransporter or sodium-glucose linked transporter are family of proteins of different types. SGLT1 transporter is found in the intestinal mucosa of the small intestine.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 25
Incorrect
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A 32 year old female is diagnosed with SLE based on her complaints of polyarthralgia, mouth ulcers and ANA positivity. Labs reveal normal urinalysis, urea and electrolytes. ESR is 90mm in the first hour. How will you manage this patient?
Your Answer: Six monthly pulses of cyclophosphamide (2 mg/kg)
Correct Answer: Hydroxychloroquine 200 mg/day
Explanation:Hydroxychloroquine is used in the management of SLE as it prevents disease progression and has relatively mild side effects, for instance headache, nausea etc. Its use reduces the usage of corticosteroids. It is particularly effective when the disease is less severe and there is no organ involvement. Cyclophosphamide and prednisolone are indicated in cases of renal, neurological and lung involvement.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 26
Incorrect
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The V wave in the jugular pulse is caused by:
Your Answer: Atrial contraction
Correct Answer: Atrial filling
Explanation:The v wave reflects the passive increase in pressure and volume of the right atrium as it fills in late systole and early diastole.
The jugular vein pulsations usually have two elevations and two troughs. The first elevation (a wave) corresponds to the slight rise in atrial pressure resulting from atrial contraction. The first descent (x descent) reflects a fall in atrial pressure that starts with atrial relaxation. The second elevation (v wave) corresponds to ventricular systole when blood is entering the right atrium from the vena cavae while the tricuspid valve is closed. Finally, the second descent (y descent) reflects falling right atrial pressure as the tricuspid valve opens and blood drains from the atrium into the ventricle.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 27
Incorrect
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Iron absorption occurs primarily in which part of the GIT?
Your Answer: Jejunum
Correct Answer: Duodenum
Explanation:Like most mineral nutrients, the majority of the iron absorbed from digested food or supplements is absorbed in the duodenum by enterocytes of the duodenal lining.
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This question is part of the following fields:
- Haematology
- Medicine
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Question 28
Incorrect
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Which of the following is not a feature of Liddle’s syndrome?
Your Answer: Alkalosis
Correct Answer: Autosomal recessive inheritance
Explanation:Liddle’s syndrome is a rare autosomal dominant condition characterized by early, and frequently severe, high blood pressure associated with low plasma renin activity, metabolic alkalosis, low blood potassium, and normal to low levels of aldosterone. Liddle syndrome involves abnormal kidney function, with excess reabsorption of sodium and loss of potassium from the renal tubule, and is treated with a combination of low sodium diet and potassium-sparing diuretic drugs (e.g., amiloride).
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 29
Incorrect
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A 64 year old female presents with sudden onset pain, swelling and stiffness in her right knee. Her medical history is significant for osteoarthritis affecting her hand joints and diet controlled diabetes mellitus. On examination, the right knee is swollen, erythematous and tender. Which of the following tests would be most useful in the diagnosis of this case?
Your Answer: A trial of colchicine
Correct Answer: Aspiration and examination of the synovial fluid
Explanation:Arthrocentesis should usually be done when there is a suspicion of pseudogout or septic arthritis as in this case which leads to an early diagnosis and prompt treatment. Polarized microscopy demonstrates weakly positively birefringent rhomboid crystals which are blue when parallel to light and yellow when perpendicular to light. Elevated serum uric acid levels that cause gout are usually found after large consumption of alcohol or meat, or post surgery. Autoimmune diseases like SLE, RA etc require an autoimmune screen.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 30
Incorrect
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In Restriction Fragment Length Polymorphism (RFLP), the DNA fragments are separated by length through a process known as:
Your Answer:
Correct Answer: Gel electrophoresis
Explanation:Samples of DNA from individuals are broken into pieces by restriction enzymes and the fragments are separated according to their lengths via gel electrophoresis. Although now largely obsolete due to the rise of inexpensive DNA sequencing technologies, RFLP analysis was the first DNA profiling technique inexpensive enough to see widespread application.
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This question is part of the following fields:
- Genetics
- Medicine
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SESSION STATS - PERFORMANCE PER SPECIALTY
