Example MCQs Flashcards
A man with renal failure undergoes continuous ambulatory peritoneal dialysis. He develops peritonitis as a result of biofilm development on the indwelling catheter used for the delivery of exchange fluid into the peritoneal cavity. This is identified as a coagulase negative staphylococcal infection, caused by commensal bacteria, which usually exists harmlessly as part of the flora. Where is the causative agent usually found?
- A) bladder
- B) blood
- C) colon
- D) duodenum
- E) skin
E) skin
Brain natriuretic peptide can be used as a serum biomarker for heart failure.
What actions do natriuretic peptides have? Where are these peptides released from.
- Increases renin secretion
- Increases total peripheral resistance
- Increases Na+ reabsoprtion
- Increases GFR (glomerular filtration rate)
Increases GFR (glomerular filtration rate)
- Many neuropathic conditions result from changes in the electrical activity of peripheral neurons.
What do these cellular level changes do?
- Facilitate sub-threshold depolarisation
- Increase action potential duration
- Increase the excitation threshold
- Lower the excitation threshold
- Reduce neurotransmitter release
Facilitate sub-threshold depolarisation
A man is due to undergo radiotherapy for prostate cancer. This treatment depends on radiation to remove an electron from an atom or molecule, thus generating free radicals. Which type of radiation would be most suitable for this purpose?
- A) gamma
- B) infrared
- C) microwaves
- D) radiowaves
- E) UV
A) gamma
People with a rare disorder called von Hippel-Lindau (VHL) syndrome lack atumour suppressor protein (pVHL) that under normal oxygen tension causes ubiquitination of hypoxia-inducible factor (HIF). Lack of pVHL triggers the continual production of VEGF resulting in ‘hemangioblastomas’, tumours that contain dense masses of blood vessels.
What is the consequence of the action of pVHL?
- Decreased transcription of the HIFα subunit
- Increased dimerisation of HIFα and HIFβ subunits
- Proteolytic degradation of the HIFα subunit
- Triggering of apoptotic cell death
- Triggering of a phosphorylation cascade
Proteolytic degradation of the HIFα subunit
You are doing a pHD examining the cell death in leukocytes an you need to be able to quantify the % of apoptotic cells in a population of isolated cells. Apoptosis is a form of cell death in which phosphatidylserine becomes exposed on the outer surface of dying cells, this can measure apoptosis. Which lab technique would be most appropriate to use to achieve this?
- A) ELIZA
- B) flow cytometry
- C) immunohistochemistry
- D) PCR
- E) western blotting
B) flow cytometry
You profile bacteria present in sample of untreated water from streams across the south west. You perform gram-staining on the bacteria and find blue-purple stained spherical bacteria, arranged in chains, under the microscope light. What type of micro-organism is present?
- A) Gram-negative cocci
- B) Gram-negative diplococci
- C) Gram-negative Rods
- D) Gram-positive rods
- E) Gram-positive cocci
E) Gram-positive cocci
Ubiquitination is a protein post-translational modification process, that attaches ub to a protein. This process plays an important role in the HIF pathway by marking HIF-1a for degradation. What is ub?
- A) amino acid
- B) inorganic chemical
- C) methyl
- D) protein
- E) sugar moiety
D) protein
Darifenasin is a selective m3-muscarinic receptor antagonist. What effect will this have on bladder function?
- A) relax internal sphincter
- B) relax bladder detrusor muscle
- C) Constrict internal sphincter
- D) contract bladder detrusor muscle
- E) relax external sphincter
B) relax bladder detrusor muscle
Ubiquitination is a protein post-translational modification process that attaches ubiquitin to the protein. This process plays an important role in the HIF pathway, by marking HIF-1a for degradation. What is ubiquitin?
- A) protein
- B) amino acids
- C) inorganic chemicals
- D) metal ion
- E) sugar moiety
A) protein
You are working in a research lab, and wish to create a transgenic mouse model, characterised by defective uptake of glucose into pancreatic beta cells. To achieve this you would need to alter the gene encoding which protein?
- A) Glut 2
- B) Glut 4
- C) Insulin receptor
- D) NA/glucose antiporter
- E) Na/glucose transporter
A) Glut 2 glut 2 is a glucose transporter found on cell membranes of pancreatic beta cells.
Scavenger receptors recognise anionic polymers acetylated low density proteins. The CD14 receptor binds to LPS. Which toll like receptor does this activate?
- A) TLR2
- B) TLR4
- C) TLR5
- D) TLR6
- E) TLR7
B) TLR4
Binding a hedgehog ligand to the patched-1 receptors activates a smoothened, which results in the transcription of genes involved with embryonic patterning and limb development. What prevents this process from occuring in the absence of stimulus.
- A) Binding of an inhibitory molecule to smoothened
- B) Dephosphorylation of smoothened
- C) Steric hindrance of smoothened translocation
- D) Lack of transcription of smoothened
- E) Ubiquitination and proteasomal degradation of smoothened
C) Steric hindrance of smoothened translocation
The pathogenesis of Alzheimer’s Disease remains unclear. A role forapolipoprotein E (ApoE) has been implicated, and deletion of 16 base pairs from exon 3 of the gene encoding ApoE represents a reliable mouse model of the disease.
Which function is commonly reduced in this disorder?
- Balance
- Retrieval of new information
- Retrieval of old information
- Spatial awareness
- Storage of new information
Storage of new information
C reactive protein is an acute phase protein found in the blood. The levels rise in response to inflammation. Which organ releases this protein?
- A) kidney
- B) liver
- C) pancreas
- D) spleen
- E) thymus
B) liver
The TGN 1412 clinical trial made headlines in 2006 as a result of several side effects in 6 individuals given a potential new super-agonist drug during phase 1 trials. What was the primary purpose of the trial?
- A) compare new drug with gold standard
- B) determine effectiveness of new drug
- C) determine the safety of the new drug
- D) establish the optimal dose
- E) Establish optimal mode of administration
C) determine the safety of the new drug
CDKs are constitutively presenting cells, but become activated by the cell cycle, stage dependent transcription of cyclins such as cyclin E. Which CDK is activated by this cyclin?
- A) CDK 1
- B) CDK 2
- C) CDK 3
- D) CDK 4
- E) CDK 5
B) CDK 2 mitogen independent in late G1
You are working in a public health laboratory, and are asked to carry out ahaemagglutination inhibition assay on serum samples from three patients with suspected H1N1 influenza. You are asked to include information on the H1 status of the samples and the HI titres in your report. Red blood cells are added to a 96-well plate containing a mixture of viral H1 haemagglutinin and diluted patient serum. The results are shown in the image.
What information should you put in your report?
- Patient 1: Negative
- Patient 2: Positive (titre <2)
- Patient 3: Negative
- Patient 1: Negative
- Patient 2: Positive (titre >4096)
- Patient 3: Negative
- Patient 1: Positive (titre 16)
- Patient 2: Negative
- Patient 3: Positive (titre 256)
- Patient 1: Positive (titre 32)
- Patient 2: Negative
- Patient 3: Positive (titre 512)
- Patient 1: Positive (titre 32)
- Patient 2: Positive (titre <2)
- Patient 3: Positive (titre 512)
- Patient 1: Positive (titre 16)
- Patient 2: Negative
- Patient 3: Positive (titre 256)
Photoreceptors are specialised cells in the retina. Their activity is modulated inresponse to light which has passed through the eye.
What effect does light have on neurotransmitter release from these cells?
- Decrease in GABA release
- Decrease in glutamate release
- Increase in acetylcholine release
- Increase in GABA release
- Increase in glutamate release
Decrease in glutamate release
Cell death can be assessed in the lab, including visualization of chromatin condensation, membrane blebbing or uptake of dye. e.g. trypan blue by microscopy. Other methods involve assessment of DNA laddering by gel electrophoresis and activation of caspase enzymes by fluorescence based methods. A +ve result in which method would indicate necrosis, not apoptosis?
- A) Caspase activation
- B) Chromatin condensation
- C) DNA laddering
- C) Membrane blebbing
- D) Uptake of dye
D) Uptake of dye
You are revising muscular contraction. Both skeletal muscle, and non-pacemaker regions of the heart depend on electrical excitation of the myocytes and myofibres, by an AP. You note the shape and duration of the AP is different. These differences can be explained by which ionic current.
- A) Inward long lasting ca current
- B) Inward transient ca current
- C) Inward fast sodium current
- D) Inward slow sodium current
- E) Outward Potassium current
A) Inward long lasting ca current
Pre-eclampsia in pregnant women is characterised by loss of protein in theurine (proteinuria) and high blood pressure.An inappropriate autoimmune response that activates the angiotensin receptor subtype 1 (AT ) has been implicated in the pathophysiology of this condition. Activating (agonistic) autoantibodies against the AT1 may be found in the serum of some patients with pre-eclampsia.
What endocrine pattern would be expected in a patient with these autoantibodies?
A. High aldosterone, high renin, high angiotensin II
B. High aldosterone, low renin, high angiotensin II
C. High aldosterone, low renin, low angiotensin II
D. Low aldosterone, low renin, low angiotensin II
C. High aldosterone, low renin, low angiotensin II
Autoimmune diseases such as inflammatory bowel diseases and MS, are characteristically associated with a recently identified subset of T cells, known as TH-17. Which cytokine particularly promotes the proliferation of these cells.
- A) IL-2
- B) IL-4
- C) IL-6
- D) IL-17
- E) IL-23
E) IL-23
You are carrying out a study investigating WNT signalling in breast cancer tumorigenesis. You create a transgenic mouse that overexpresses wnt in mammary tissue, and observe an upregulation of wnt binding to its receptor. Which protein is subsequently recruited to the ligand receptor complex?
- A) APC
- B) Axin
- C) B-catenin
- D) Dishevelled
- E) GSK3b
D) Dishevelled
Acid-base balance is essential for maintaining plasma protein integrity andfunction. Hydrogen ions are secreted into the lumen of the nephron in the proximal and late distal convoluted tubule in order to reduce the acidic load within the body.
What is the mechanism by which this secretion occurs in the proximal tubule?
- Antiport with K+
- Antiport with Na+
- Symport with Cl-
- Symport with K+
- Symport with Na+
B. Antiport with Na+
The ischaemic cascade involves many processes which cumulate in neural deficit and cell death. Reduction in the neural level of which molecule starts the cascade?
- A) Calcium
- B) ATP
- C) Sodium
- D) Glutamate
- E) Superoxide
B) ATP
A 24 year old women had a number of episodes of visual disturbance. Following a number of tests including Identification of auto-antibodies she was told she had MS. What type of sample would be most appropriate for the detection of these auto-antibodies?
- A) Blood
- B) CSF
- C) Saliva
- D) Tissue Biopsy
- E) Urine
B) CSF
Which artery is most frequently occluded in stroke patients
- A) Anterior cerebral artery
- B) Middle cerebral artery
- C) Posterior cerebral artery
- D) Lenticulostriate artery
- E) Carotid artery
B) Middle cerebral artery
Erythrocytes sedimentation rate (ESR) is a measurement used as a marker of inflammation. Which component of the blood rises during inflammation to cause an increase in this measurement?
- A) Fibrinogen
- B) Folate
- C) Heparin
- D) Thrombospondin
- E) TPA
A) Fibrinogen This is an acute phase protein, in response to IL-6. High conc’s = RBCs more sticky and settle faster. ESR - rate at which RBCs sediment in one hour.
A needle phobic patient is having blood samples taken and has a sympathetic nervous system response during this. Most of this is brought on by the action of noradrenaline from post-ganglionic sympathetic neurons, on adrenoreceptors. What part of this response is from Ach on muscarinic receptors?
- Adrenaline release
- Bronchodilation
- Sweating
- Tachycardia
- Vasoconstriction
3 Sweating
A patient is describing how his partial focal epileptic seizures are experienced. He says I lose my ability to speak, Its weird I know what I want to say but i can’t get the words out. Which regions of the brain is most likely affected.
- A) cerebellum
- B) frontal lobe
- C) occipital lobe
- D) parietal lobe
- E) temporal lobe
B) frontal lobe
There are many different strains of influenza virus. Influenza viruses can beclassified according to their surface antigens, haemagglutinin (H) and neuraminidase (N).
How does the ‘N’ antigen assist in influenza infection?
- Facilitates evasion of host immune response
- Facilitates incorporation of viral DNA into the human genome
- Facilitates release of virions from infected cells
- Facilitates viral DNA replication
- Facilitates viral entry into human cells
Facilitates release of virions from infected cells
- The Baltimore classification of viruses, categorises viruses according to theirmethod of viral mRNA synthesis.
Which virus classifications mutate more frequently?
- Group I: dsDNA
- Group II: (+) ssDNA to dsDNA
- Group III (dsRNA)
- Group IV (+) ssRNA to (-) ssRNA
- Group V (-) ssRNA
- Group VI (+) ssRNA - DNA/RNA - dsDNA
Group VI (+) ssRNA - DNA/RNA - dsDNA
You are starting a research group focusing on protein misfolding disorders. The fast and effective folding of newly synthesised proteins is catalysed by which class of enzyme?
- A) chaperonins
- B) cyclophilins
- C) peptidal dipepetides
- D) peptidal procis-transisomerases
- E) protein disulphide isomerases
A) chaperonins
True or False- the parasympathetic preganglionic neuron is long and releases Ach
True
A 20 year old bodybuilder follows an extreme high-calorie diet that includes 15 bananas a day. The resulting potassium load causes elevation of aldosterone release, thereby increasing urinary excretion of potassium.
Where in the nephron does this hormone have its major effect?
- Thick ascending Loop of Henle
- Decending Loop of Henle
- Early proximal convoluted tubule
- Late distal convoluted tubule
- Thin Ascending Loop
D. Late distal convoluted tubule
The term sarcopenia describes the loss of skeletal muscle mass, and strength that occurs with biological ageing. Which of the following hormonal, immunological alterations is thought to contribute to the development of sarcopenia?
- A) increased GH
- B) Increased IGF-1
- C) increased myostatin
- D) increased oestrogen
- E) increased testosterone
C) increased myostatin
A 43 year old man is prescribed medication for schizophrenia. Over time, hedevelops hypogonadism and suffers from erectile dysfunction. Blood tests reveal a serum prolactin concentration that is twice the normal concentration.
These symptoms have arisen from blockade of which system in the CNS?
- Hypothalamo-pituitary axis
- Corticospinal tract
- Mesocortical pathway
- Mesolimbic pathway
- Tuberoinfundibular pathway
Tuberoinfundibular pathway
You are recording the ST segment of an ECG trace. What does this period of time represent?
- A) Duration of conduction through AVN
- B) HR of patient
- C) Time between atrial depolarisation and repolarisation
- D) Time between atrial depolarisation and ventricular repolarization
- E) Time between ventricular depolarisation and repolarisation
E) Time between ventricular depolarisation and repolarisation Largest deflections (RT) - ventricular AVN spreads –> Atria (P) –> Septum (Q) –> Ventricles (R) –> Purkinje (S) –> Repolarisation (T)
Many pharmacological agents act as receptors, which convert a chemical signal into a physiological response. Different classes of receptor exist, which use different mechanisms to convert the signal into a response. Which of the following would elicit the most rapid physiological response.
- A) B1 adrenergic receptor
- B) EPO receptor
- C) Glucocorticoid receptor
- D) M2 Acetylcholine receptor
- E) Nicotinic acetylcholine receptor
E) Nicotinic acetylcholine receptor
Working as an NHS Clinical Scientist, you are asked to evaluate brain slicestaken from the autopsied brain of a Parkinson’s disease sufferer.
In which region would you expect to see evidence of neuronal degeneration?
- Globus Pallidus
- Hypothalamus
- Raphe nuclei
- Substantia nigra
- Thalamus
Substantia nigra
You receive a CSF analysis from a patient with: -Cloudy/Turbid -Protein 105 (15-50) -Glucose 40 (45-100) -WBC 550 (0-5) -WBC 85% Neutrophils What disease does the patient have?
- A) B meningitis
- B) V meningitis
- C) Guillain-Barre
- D) MS
- E) Syphilis
A) B meningitis
COX inhibitors have been used as antiinflammatory agents for many years, however some of these drugs carry a risk of stroke, or MI due to inappropriate blood clotting, resulting from non-specific inhibition of arachidonic acid metabolism. What other enzyme in this pathway could be specifically inhibited to reduce the risk of clotting.
- A) Lipoxygenase
- B) Phospholipase C
- C) Prostacyclin Synthase
- D) Prostaglandin E synthase
- E) Thromboxane synthase
E) Thromboxane synthase
A single tumour cell has detached from a primary tumour. But has failed to undergo detachment mediated cell death- and has not yet entered the blood or lymph. Which potential therapeutic strategy could target the next step in the metastatic process.
- A) Inhibition of CDK
- B) T regs
- C) VCAM-1
- D) VEGF
- E) MMPs
E) MMPs 2nd step: Detached cell must adhere and invade the basement membrane by increasing protease (MMP) activity. It can then migrate through the extracellular matrix and into surrounding tissue.
A new drug for hypertension is being investigated including a calculation of its bioavailability after oral administration. When given orally some drugs can be extensively broken down into inactive metabolites after absorption from the GI tract (first pass metabolism), so they are largely unavailable for therapeutic activity. Where does this metabolism occur?
- A) gall bladder
- B) kidney
- C) liver
- D) pancreas
- E) spleen
C) liver
Skeletal muscle contraction requires opening of ion channels known as DHP receptors on the sarcolemma. Which type of ion channels are these?
- A) ligand gated CA channel
- B) ligand gated K channels
- C) VG ca channels
- D) VG K channels
- E) VG NA channels
C) VG ca channels
A 12 month old baby is found producing insufficient amounts of factor VIII to mediate blood clotting. Which step in the clotting process is deficient
- A) activation of factor IX
- B) activation of factor V
- C) activation of factor X
- D) conversion of fibrinogen to fibrin
C) activation of factor X Last step of the intrinsic pathway
What enzyme at the neuromuscular junction terminates neurotransmitter signalling to the motor endpoint
- A) AchE
- B) Adenylate cyclase
- C) Acetyl CoA
- D) Phospholipase C
- E) SERCA
A) AchE
The APC gene (mutations in the gene lead to a hereditary form of bowel cancer) is a tumour suppressor which prevents excessive activation of mitotic signalling pathways. As part of a destruction complex, APC binds to target proteins, leading to their ubiquitination proteasomal degradation. Which protein is a target for this destruction complex?
- A) B-catenin
- B) frizzled
- C) patched
- D) smoothened
- E) wnt
A) B-catenin
Humans express several cyclin-dependent kinases. CDKs 4 and 6 have a role in cell cycle progression, based on their ability to phosphorylate a restriction point target. What is a key target for these CDKs.
- A) phosphatidylinositol-4,5 bisphosphate
- B) PKC
- C) Raf
- D) Ras
- E) Rb
E) Rb
a 21 year old woman becomes dehydrated following running a half marathon. As part of the hormonal response to this there is an increase in the level of aldosterone. Where is this hormone produced?
- A) Adrenal cortex
- B) Adrenal medulla
- C) Anterior Pituitary
- D) Hypothalamus
- E) Posterior Pituitary
A) Adrenal cortex
A 54 year old man develops autoimmune diabetes insipidus, where autoantibodies attack the cells which synthesis ADH. Which structure is the site of synthesis of this hormone?
- A) Adrenal glands
- B) Cardiac atria
- C) Hypothalamus
- D) Juxtaglomerular Apparatus
- E) Posterior Pituitary
C) Hypothalamus ADH is synthesised here, and released by the Posterior Pituitary gland
A boy with haemophilia has been receiving infusion of recombinant factor VIII, and has been able to lead a normal active life. However, the bleeding has become increasingly difficult to stop, showing reduced effectiveness of the therapy. This is due to an immune response against the therapeutic protein, leading to the production of inhibitory antibodies which neutralise the biological effect of the protein. What type of cell is involved in the first step of the immune response?
- A) cytotoxic T cell
- B) Dendritic cell
- C) Helper T cell
- D) Plasma Cell
- E) T reg cell
B) Dendritic cell
Once sever sepsis is identified, antibiotics must be started rapidly to treat the underlying infection. Patients are often treated with broad-spectrum cephalosporin antibiotic e.g. cefuroxime until the causative organism and its specific antibiotic susceptibilities are defined. What is the mechanism of cefuroxime?
- A) binds the 30s bacterial ribosome subunit
- B) inhibits DNA gyrase
- C) inhibits protein synthesis
- D) inhibits bacterial cell wall synthesis
- E) Inhibits tetrahydrofolic acid synthesis
D) inhibits bacterial cell wall synthesis cephalosporin ‘s are beta-lactam antibiotics, which inhibit peptidoglycan synthesis- needed for cell walls.
A 58 year old is to undergo an angioplasty, following a MI. his cardiologist tells him he intends to insert a drug-eluting stent as part of the angioplasty procedure, and will release a drug reducing the chances of the blood vessels narrowing. What type of drug would be most effective
- A) Anti-platelet drug
- B) Beta-blockers
- C) Immunosuppressants
- D) Statin
- E) Thrombolytic
C) Immunosuppressants
You are performing a radioligand binding assay comparing a novel compound Awith a radiolabelled known drug of moderate affinity. You generate the following dose-response curve.
What parameter is depicted by “X” on the graph?
- EC50
- IC 50
- Kd
- logEC50
- log IC50
log IC50
Reverse transcriptase PCR can be used to detect viral RNA in patient samples.
On which type of sample, and at which stage of infection would it be most appropriate to test patients for Influenza A virus using this test method?
A
You are working in the neurological disorders unit of a large pharmaceuticalcompany screening a number of novel neuroleptic (antipsychotic) compounds. You generate data using the heterologous competitive radioligand binding assay that will give a pharmacokinetic profile of novel compound BCS101 to investigate its affinity for the D receptor.
Varying concentrations of unlabelled BSC101 and 0.2 nM of tritium-labelled spiperone (K 0.16nM) are added to added to plasma membrane preparations from Chinese Hamster Ovary (CHO) cells that express the D receptor, and incubated until equilibrium has been reached. Following washing, measurement of cell radioactivity gives an indication of how much tritiated spiperone has bound to the D receptors. The lower the level of radioactivity, the greater the extent to which the test compound has bound to the receptors and prevented the binding of the radiolabelled spiperone.
You plot the data as shown and you read off:
log IC50= -9.2
Using the Cheng-Prussof equation, calculate the K of BCS101 i
- 0.28 nM
- 36.8 nM
- -36.8 nM
- 28 mM
- 12578517 uM
0.28 nM
You are studying the anatomy of the eye for your degree and you find thisdiagram.
What structure is labelled X?
- Macula
- Optic disc
- Optic nerve
- Retina
- Vitreous humour
Optic disc
