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Question 1
Correct
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In RFLP (restriction fragment length polymorphism), the DNA fragments are separated by length through a process known as:
Your Answer: Agarose 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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Question 2
Correct
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Visceral afferent fibers are found in the following areas except the…?
Your Answer: Trigeminal nerve
Explanation:The general visceral afferent (GVA) fibers carry impulses from viscera to the central nervous system. The cranial nerves that contain GVA fibers include the facial nerve, the glossopharyngeal nerve and the vagus nerve
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This question is part of the following fields:
- Medicine
- Neurology
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Question 3
Correct
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Which of the following may be a feature of primary hyperaldosteronism?
Your Answer: Muscular weakness
Explanation:Primary hyperaldosteronism or Conn’s syndrome is characterised by hypertension which may cause poor vision or headaches. Occasionally there may be muscular weakness, muscle spasms, tingling sensations, or excessive urination. Complications include cardiovascular disease such as stroke, myocardial infarction, kidney failure, and abnormal heart rhythms.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 4
Correct
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What is the role of cyclin and cyklin-dependent kinases in mitosis:
Your Answer: Phosphorylation of proteins that make up pre-replication complexes
Explanation:There are certain regulators of the cell cycles that mediate progression through the cell cycle. These are cyclins and cyklin-dependent kinases (CDKs). They form a complex that phosphorylates protein involved in the cell cycle.
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This question is part of the following fields:
- Genetics
- Medicine
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Question 5
Correct
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Approximately what percentage of the world is infected with tuberculosis:
Your Answer: 25%
Explanation:The WHO report states that about one-quarter of the world’s population is infected with Mycobacterium tuberculosis, the bacterium that causes tuberculosis. This means approximately 25% of people globally have latent TB infection, which can potentially progress to active TB disease.
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This question is part of the following fields:
- Infectious Diseases
- Medicine
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Question 6
Correct
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In cardiac muscle, which of the following is directly responsible for the release of Ca2+ stored in the sarcoplasmic reticulum (calcium-induced calcium release)?
Your Answer: Ryanodine receptor (RyR)
Explanation:Ryanodine receptor (RyR) is a ligand-gated Ca2+ channel with Ca2+ as its natural ligand. In skeletal muscle, Ca2+ entry from ECF by this route is not required for Ca2+ release. Instead, the DHPR that serves as the voltage sensor unlocks release of Ca2+ from the nearby SR via physical interaction with the RyR. The release is amplified through ca-induced ca release. However, in cardiac muscle, it is the influx of extracellular Ca2+ through the voltage-sensitive DHPR in the T system that triggers ca-induced ca release trough the RyR at the SR.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 7
Correct
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A 56 year old obese female presents due to moderate pain in her finger joints which occurs mostly at the end of the day which gets better with rest. There is also some associated swelling. On examination, there is enlargement of her distal interphalangeal joints and tenderness to palpation. Which of the following is the most likely diagnosis?
Your Answer: Osteoarthritis
Explanation:Osteoarthritis (OA) is a disabling joint disease characterized by a noninflammatory degeneration of the joint complex (articular cartilage, subchondral bone, and synovium) that occurs with old age or from overuse. It mainly affects the weight-bearing and high-use joints, such as the hip, knee, hands, and vertebrae. Despite the widespread view that OA is a condition caused exclusively by degenerative “wear and tear” of the joints, newer research indicates a significant heterogeneity of causation, including pre-existing peculiarities of joint anatomy, genetics, local inflammation, mechanical forces, and biochemical processes that are affected by proinflammatory mediators and proteases. Major risk factors include advanced age, obesity, previous injuries, and asymmetrically stressed joints. In early-stage osteoarthritis, patients may complain of reduced range of motion, joint-stiffness, and pain that is aggravated with heavy use. As the disease advances, nagging pain may also occur during the night or at rest. Diagnosis is predominantly based on clinical and radiological findings. Classic radiographic features of OA do not necessarily correlate with clinical symptoms and appearance. RA involves proximal interphalangeal joints not distal. Gout occurs as a result of overproduction or underexcretion of uric acid and frequently involves first toe. Fibromyalgia is a disorder characterized by widespread musculoskeletal pain accompanied by fatigue, sleep, memory and mood issues.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 8
Correct
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During bone growth-the epiphysis are separated from the diaphysis by actively proliferating cartilage known as:
Your Answer: Epiphysial plate
Explanation:The epiphysial plate, physis, or growth plate, is a hyaline cartilage plate located near the ends of long bones; it consists of growing tissue. It is found in children and teenagers; in adults, it is replaced by an epiphysial line or epiphysial closure. The epiphysial plate is divided into zones: zone of reserve, proliferation, maturation and hypertrophy, calcification, and ossification.
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This question is part of the following fields:
- Endocrinology
- Medicine
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Question 9
Incorrect
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The alpha amylases hydrolyse which linkages in the ingested polysaccharides?
Your Answer: 1:6α linkages
Correct Answer: 1:4α linkages
Explanation:Alfa amylase hydrolyses the α (1-4) glyosidic bonds in amylose and amylopectin and leave primarily maltose.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 10
Correct
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Which of the following foods contain Vitamin B 12?
Your Answer: Liver, meat
Explanation:No fungi, plants, nor animals (including humans) are capable of producing vitamin B12. Only bacteria and archaea have the enzymes needed for its synthesis. Proved food sources of B12 are animal products (meat, fish, dairy products).
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This question is part of the following fields:
- Haematology
- Medicine
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Question 11
Incorrect
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Digoxin causes:
Your Answer: Na/k ATPase stimulation
Correct Answer: Increase in cytosolic calcium concentration
Explanation:Digoxin is a positive inotrope which inhibits NA/K ATPase, increases cardiac contractility and can cause hypokalaemia.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 12
Incorrect
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An 81-year-old male presented to the emergency department following a fall at home. He was diagnosed with osteoporosis about five years ago. He presently complains of significant low back pain. A lumbar spine X-ray was suggestive of a fractured lumbar vertebra. A subsequent MRI scan of the lumbosacral spine revealed a new L3 burst fracture with no evidence of cord compression. A neurosurgical consult was sought and conservative management was planned accordingly in the form of pain control, physiotherapy, and mobilization (as allowed by the pain). He also has been diagnosed with chronic renal disease (stage IV) with a creatinine clearance of 21ml/min, he was started on a Buprenorphine patch. Which of the following opioids would be safest to use for his breakthrough pain?
Your Answer: Morphine
Correct Answer: Oxycodone
Explanation:Oxycodone is a safer opioid to use in patients with moderate to end-stage renal failure.Active metabolites of morphine accumulate in renal failure which means that long-term use is contraindicated in patients with moderate/severe renal failure. These toxic metabolites can accumulate causing toxicity and risk overdose. Oxycodone is mainly metabolised in the liver and thus safer to use in patients with moderate to end-stage renal failure with dose reductions.Adverse effects:Constipation is the most common overall side effect. Others include: asthenia, dizziness, dry mouth, headache, nausea, pruritus, etc. Medications in renal failure:Drugs to be avoided in patients with renal failureAntibiotics: tetracycline, nitrofurantoinNSAIDsLithiumMetforminDrugs that require dose adjustment:Most antibiotics including penicillin, cephalosporins, vancomycin, gentamicin, streptomycinDigoxin, atenololMethotrexateSulphonylureasFurosemideOpioidsRelatively safe drugs:Antibiotics: erythromycin, rifampicinDiazepamWarfarin
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 13
Correct
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Concerning surface anatomy, where is the mitral valve found?
Your Answer: Situated in the 4th intercostal space to the left of the sternum
Explanation:The mitral valve is situated in the left 4th intercostal space just beneath the sternum.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 14
Incorrect
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A 47-year-old male with type II diabetes mellitus presents to your clinic with a history suggestive of erectile dysfunction. You decide to start him on sildenafil citrate. What is the mechanism of action of this drug?
Your Answer: Non-selective phosphodiesterase inhibitor
Correct Answer: Phosphodiesterase type V inhibitor
Explanation:Sildenafil (Viagra) is a phosphodiesterase type V inhibitor used in the treatment of impotence.Contraindications:- Patients taking nitrates and related drugs such as nicorandil- Hypotension- Recent stroke or myocardial infarction (NICE recommend waiting 6 months)Side-effects:Visual disturbances e.g. cyanopsia, non-arthritic anterior ischaemic NeuropathyNasal congestionFlushingGastrointestinal side-effectsHeadache
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 15
Incorrect
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Endothelial cells produce the following substance(s):
Your Answer: Endothelins
Correct Answer: All of the above
Explanation:Endothelial cells produce thromboxane, prostacyclins, nitric oxides, endothelins, IL-1 and TNF.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 16
Correct
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Bile acids will be prevented from being absorbed by resection of which part of the gastrointestinal tract?
Your Answer: Ileum
Explanation:Bile acids (also called bile salts) are produced in the liver, secreted into the biliary system, stored in the gallbladder and are released after meals stimulated by cholecystokinin. They are important for the digestion and absorption of fats (lipids) in the small intestine. Usually over 95% of the bile acids are absorbed in the terminal ileum and are taken up by the liver and resecreted.
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This question is part of the following fields:
- Medicine
- Metabolism
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Question 17
Correct
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A 35-year-old man was brought to the ER with acute confusion. He's a known case of bipolar disorder under treatment with mood stabilizers. Blood investigations revealed lithium toxicity. A decision is made to start the patient on sodium bicarbonate. What is the rationale behind the use of sodium bicarbonate in this patient?
Your Answer: Increases urine alkalinity
Explanation:The rationale behind the use of sodium bicarbonate is that it increases the alkalinity of the urine promoting lithium excretion. The preferred treatment in severe cases would be haemodialysis.Lithium is a mood-stabilizing drug used most commonly prophylactically in bipolar disorder but also as an adjunct in refractory depression. It has a very narrow therapeutic range (0.4-1.0 mmol/L) and a long plasma half-life being excreted primarily by the kidneys. Lithium toxicity generally occurs following concentrations > 1.5 mmol/L.Toxicity may be precipitated by dehydration, renal failure, diuretics (especially Bendroflumethiazide), ACE inhibitors, NSAIDs and metronidazole.Features of toxicityCoarse tremor (a fine tremor is seen in therapeutic levels)HyperreflexiaAcute confusionSeizureComaManagementMild-moderate toxicity may respond to volume resuscitation with normal salineHaemodialysis may be needed in severe toxicitySodium bicarbonate is sometimes used but there is limited evidence to support this. By increasing the alkalinity of the urine it promotes lithium excretion.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 18
Incorrect
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A 56 year old woman taking procainamide develops drug induced erythematosus. Which of the following features is the most characteristic of this condition?
Your Answer: The symptoms may be alleviated with long-term steroids
Correct Answer: It may occur with chlorpromazine
Explanation:Drug induced lupus is usually positive for antinuclear and antihistone antibodies, typically without renal or neurologic involvement. However, pulmonary involvement is common. Drugs that can induce lupus include isoniazid, hydralazine, procainamide, chlorpromazine, and other anticonvulsants.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 19
Incorrect
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A 32 year old man presents with blistering and hyperpigmentation on his face and hands, after a beach holiday with friends. Tests reveal high levels of uroporphyrinogen in the urine. The most likely diagnosis is:
Your Answer: Acute intermittent porphyria
Correct Answer: Porphyria cutanea tarda
Explanation:Porphyria cutanea tarda (PCT) is the most common of the porphyries. It is characterised by fragility and blistering of exposed skin. Typically, patients who are ultimately diagnosed with PCT first seek treatment following the development photosensitivities in the form of blisters and erosions on commonly exposed areas of the skin. This is usually observed in the face, hands, forearms, and lower legs. It heals slowly and with scarring. Though blisters are the most common skin manifestations of PCT, other skin manifestations like hyperpigmentation (as if they are getting a tan) and hypertrichosis (mainly on top of the cheeks) also occur. Risk factors for the development of PCT include alcohol and sun.
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This question is part of the following fields:
- Dermatology
- Medicine
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Question 20
Correct
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In a 70 kg male, the approximate volumes (litres) of water in the different compartments mentioned (intracellular, interstitial, vascular) are:
Your Answer: 28l, 14l, 3.5l
Explanation:In a 70kg male, approximately 60% (42 L) of the total body weight is composed of water divided proportionally in the following compartments:Intracellular fluid (ICF) – Around 67% (28 L) of total body water.Extracellular fluid (ECF) – Approximately 33% (14 L) of the total body fluid. The fluid in the intravascular compartment is about 3 L and is generally about 25% of the volume of ECF.
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This question is part of the following fields:
- Medicine
- Renal
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Question 21
Incorrect
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Regarding the length of systole and diastole which of the following is true?
Your Answer: Cardiac muscle can be tetanise
Correct Answer: The duration of systole is more fixed than diastole
Explanation:The duration of systole is more fixed than the duration of diastole. When the heart rate increases the timing of systole remains more or less the same however, diastole decreases.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 22
Correct
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Which of the following is correct regarding lead poisoning?
Your Answer: Causes a peripheral neuropathy due to demyelination
Explanation:Lead can be absorbed through the skin and by inhalation. It is associated with iron deficiency and a microcytic anaemia. The most common gastrointestinal symptoms are abdominal colic and constipation.
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This question is part of the following fields:
- Medicine
- Pharmacology
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Question 23
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 24
Correct
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If O2 makes up 21% of air, then at one atmosphere (760mmHg) it would be expected that the PO2 of inspired air should be 0,21 x 760 = 160mmHg. In the alveoli the actual measure is 149mmHg because…
Your Answer: Water is equilibrated with air
Explanation:There are several factors that determine the value of alveolar partial oxygen pressure including: the pressure of outside air, the partial pressure of inspired oxygen and carbon dioxide, the rates of total body oxygen consumption and carbon dioxide production, the rates of alveolar ventilation and perfusion. The alveolar partial pressure is lower than the atmospheric oxygen partial pressure. One reason is, as the air enters the lungs, it is humidified by the upper airway and thus the partial pressure of water vapour reduces the oxygen partial pressure as water is equilibrated with air.
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This question is part of the following fields:
- Medicine
- Respiratory
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Question 25
Correct
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A 35 year old sales representative presents with severe pain going down her neck and right arm. She admits that this pain is worse on sitting and driving for long periods. Past history is significant for two previous road traffic accidents. Examination reveals weakness and sensory loss over C5/C6 nerve distribution. There is pain with neck movement and particularly extension. Which of the following investigations would be the most helpful in this case?
Your Answer: MRI scan of the cervical spinal cord
Explanation:Cervical radiculopathy is usually due to compression or injury to a nerve root by a herniated disc or degenerative changes. Levels C5 to T1 are the most commonly affected. It is usually, but not always, accompanied by cervical radicular pain, a sharp and shooting pain that travels from the neck and down the upper limb and may be severe. This needs to be differentiated from pain referred from the musculoskeletal (somatic) structures in the neck, which may be aching rather than sharp, and is more severe in the neck than in the upper limb. The neurological signs of cervical radiculopathy depend on the site of the lesion. The patient may have motor dysfunction, sensory deficits or alteration in tendon reflexes. While pain is a common presenting symptom, not all radiculopathies are painful (i.e. only motor deficits may be obvious). CT scanning cannot accurately demonstrate the commonest cause for cervical radiculopathy (disc herniation) without myelography, which requires hospital admission, lumbar puncture and the use of contrast. In patients with cervical radiculopathy, MRI is the imaging technique of choice for the detection of root compression by disc herniation and osteophytes. MRI allows the nerve roots to be directly visualised. Nerve conduction studies are also useful in determining the nerve roots that are involved.
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This question is part of the following fields:
- Connective Tissue
- Medicine
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Question 26
Correct
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Which lipoprotein is responsible for lowering of plasma lipids?
Your Answer: HDL
Explanation:High-density lipoproteins (HDL) are one of the five major groups of lipoproteins. Lipoproteins are complex particles composed of multiple proteins which transport all fat molecules (lipids) around the body within the water outside cells. Unlike the larger lipoprotein particles which deliver fat molecules to cells, HDL particles remove fat molecules from cells.
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This question is part of the following fields:
- Medicine
- Metabolism
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Question 27
Correct
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The following are Gram-negative cocci:
Your Answer: Neisseria
Explanation:Gram-negative cocci include the four types that cause a sexually transmitted disease (Neisseria gonorrhoeae), a meningitis (Neisseria meningitidis), and respiratory symptoms (Moraxella catarrhalis, Haemophilus influenzae).
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This question is part of the following fields:
- Infectious Diseases
- Medicine
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Question 28
Incorrect
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The ‘c’ wave in JVP corresponds more closely with:
Your Answer: Non-isovolumetric contraction
Correct Answer: Isovolumetric contraction
Explanation:The jugular venous pressure (JVP, sometimes referred to as jugular venous pulse) is the indirectly observed pressure over the venous system via visualization of the internal jugular vein. It can be useful in the differentiation of different forms of heart and lung disease. Classically three upward deflections (peaks) and two downward deflections (troughs) have been described:The upward deflections are the a (atrial contraction), c (ventricular contraction and resulting bulging of tricuspid into the right atrium during isovolumetric systole) and v = venous filling.The downward deflections of the wave are the x (the atrium relaxes and the tricuspid valve moves downward) and the y descent (filling of ventricle after tricuspid opening).
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This question is part of the following fields:
- Cardiovascular
- Medicine
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Question 29
Incorrect
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Which one of the following statements best describes a type II statistical error?
Your Answer: The null hypothesis is rejected when it is true
Correct Answer: The null hypothesis is accepted when it is false
Explanation:In statistical hypothesis testing there are 2 types of errors:- type I: the null hypothesis is rejected when it is true – i.e. Showing a difference between two groups when it doesn’t exist, a false positive. – type II: the null hypothesis is accepted when it is false – i.e. Failing to spot a difference when one really exists, a false negative.
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This question is part of the following fields:
- Medicine
- Research Skills
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Question 30
Incorrect
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Angina pectoris develops when blood through the coronary artery becomes:
Your Answer: Atherosclerotic
Correct Answer: Restricted, limiting blood blow
Explanation:Angina pectoris develops when stenosis ( >70%) of the artery occurs as a result of formation of an atherosclerotic plaque. This leads to a decrease in the O2 carried to the thickened heart muscle by the blood, leading to the characteristic chest pain associated with angina pectoris.
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This question is part of the following fields:
- Cardiovascular
- Medicine
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SESSION STATS - PERFORMANCE PER SPECIALTY
