BMS2 MOCK EXAM Questions Only PDF

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BMS2 MOCK EXAM -45min Part A -30min 1- Concerning the action of a drug at a receptor, the term “efficacy” is best defined as: A. a measure of the drug’s ability to bind to one type of receptor and not another. B. the ability of a drug to inhibit a receptor. C. the ability of the drug to activate a receptor once bound to it. D. the ability of the drug to bind to the receptor. E. the ability to modulate a receptor by binding to a site distinct from the agonist binding site.

2- In the human, water: A. cannot move through the phospholipid bilayer that surrounds cells. B. is actively transported across the plasma membranes of cells. C. is mainly transported across the plasma membranes of cells down gradients of hydrostatic pressure. D. movement across capillary endothelia is not affected by gradients of hydrostatic pressure. E. moves across cell membranes up gradients of osmotic pressure.

3- In the 'knee-jerk' reflex, which is initiated by stretch of muscle spindles in quadriceps muscle: A. Activation of the muscle spindle will cause a decrease in firing frequency of the motorneurone innervating the same muscle. B. The reflex arc includes multiple synapses between the primary sensory afferent and the motorneurone innervating the same muscle. C. The reflex is designed to measure muscle tension as the sensory receptor is in parallel with the extrafusal muscle fibres. D. The sensory afferent neurone releases the inhibitory neurotransmitter GABA in the spinal cord. E. Stretch of the muscle will increase action potential frequency in the primary sensory afferent.

4- For a typical mammalian excitable cell, the intracellular and extracellular fluid concentrations of K + ions are, respectively: A. 5 mM and 140 mM B. 140 mM and 5 mM C. 5 M and 140 M D. 140 µM and 5 µM E. 5 µM and 140 µM

5- The relative refractory period of the action potential: A. if increased in duration would increase action potential frequency. + B. is largely determined by inactivation of voltage -gated Na channels. C. is the period during maximal depolarisation. D. is the period during which another action potential cannot be generated. + E. results from hyperpolarisation due to slow closure of voltage – gated K channels.

6- Unidirectional action potential propagation is largely determined by: A. K + channel closure preventing potassium efflux. B. K+ channel opening resulting in potassium influx. C. Na + channel inactivation leading to excessive sodium influx. D. Na + channel inactivation preventing sodium influx. E. The activity of the sodium pump. 7- Which one of the following statements concerning receptor-activated signal transduction pathways is TRUE? A. Cyclic AMP stimulates protein kinase C (PKC) resulting in phosphorylation of effector molecules. B. Diacylglycerol (DAG) has its effects through the direct stimulation of Ca 2+ release from intracellular stores. C. Hydrolysis of phosphatidylinositol 4,5 bisphosphate (PIP2) by phospholipase C (PLC) produces two distinct signal transduction molecules. D. G protein βƴ subunits from the G protein Gq directly inhibit the release of Ca 2+ from intracellular stores. E. The α subunit of Gs stimulates phosphodiesterase to produce cyclic AMP.

8- In skeletal muscle excitation contraction (EC) coupling: A. At rest, concentrations of calcium are higher in the cell cytosol than in the sarcoplasmic reticulum. B. Concentration is terminated by re-uptake of calcium by the sarcoplasmic calcium ATPase (Ca-pump). C. Extracellular calcium is the major source of calcium to drive contraction. D. Noradrenaline is the major neurotransmitter released from motorneurones. E. The T-tubule is an intracellular organelle.

9- Which of the following best describes the mechanism of postganglionic sympathetic transmission in the sweat glands? A. Acetylcholine acting on muscarinic receptors B. Acetylcholine acting on nicotinic receptors C. Adrenaline acting on adrenoceptors D. Noradrenaline acting on α-adrenoceptors E. Noradrenaline acting on β-adrenoceptors

10- Which of the following removes acetylcholine from parasympathetic synapses? A. B. C. D. E.

Acetylcholinesterase Catechol-O-methyl transferase Choline acetyltransferase Monamine Oxidase Tyrosine hydroxylase

11- Which of the following statements about synaptic integration is FALSE? A. A neuron’s response to activation of two inputs depends on their relative timing. B. Coincident activation of two excitatory inputs is more likely to trigger an action potential than activation of either input alone. C. Excitatory synaptic inputs always move the membrane potential towards spike threshold. D. Inhibitory synaptic inputs always move the membrane potential away from spike threshold. E. The threshold potential at which excitatory responses trigger action potentials is in part determined by Na + channels. 12- Which of the following is a characteristic of GABA A receptors? A. A tetrameric structure B. Activated by actetylcholine C. Couple directly to G-proteins D. Mediate action potentials E. Permeability to Cl ions

13- Which of the following statements applies to menstrual cycles, but NOT to oestrous cycles? A. Cycles can be further subdivided into spontaneous or induced. B. Females are sexually receptive throughout the cycle. C. Females exhibit markedly altered behaviour at the time of ovulation. D. Males exhibit the Flehmen response. E. Ovulation can occur at any stage of the menstrual cycle.

14- The female germ cell (oocyte) needs to be in contact with what cell type in order to grow and develop? A. Granulosa cells B. Leydig cells C. Other oocytes D. Sertoli cells E. Thecal cells

15- Which receptors determine the response of the lungs to irritants? A. Adrenoceptors B. Baroreceptors C. Juxtapulmonary capillary receptors D. Rapidly adapting receptors E. Slowly adapting receptors

16- What structure is thought to determine the body’s entire respiratory response to hypoxia?

A. B. C. D. E.

The alveoli The baroreceptors The carotid bodies The cerebral cortex The pulmonary arteries

17- You analysed an experiment that examined how a drug influenced the rate of neuron firing. The mean rate of neuron firing was 17% higher in the presence of the drug, and a randomization test that assessed differences between the drug presence/absence groups yielded a p-value = 0.01. This result means: A. We can say with absolute certainty that the drug increases the rate of neuron firing B. 1% of the Null distribution for this analysis has results that are as or more extreme than the one obtained by your experiment. C. We can reject the Alternative hypothesis D. There is a 1% chance that the Null hypothesis is incorrect

18- Interpret the following R command: data...