lOMoARcPSD 3454541 Exam 15 April 2016 questions and answers Introductory Biology Comparative Physiology Cornell University StuDocu is not sponsored or endorsed by any college or university Downloaded by yelena radutskaya radutskaya yahoo com lOMoARcPSD 3454541 Name Prelim 2 BioG 1440 SP16 April 15 2016 Total pages in exam including cover 7 WATCH YOUR TIME This is a 50 minute test Name Student ID By signing below I acknowledge that I am abiding by Cornell University s Code Signature PLEASE 1 WRITE YOUR NAME on all pages of the exam 2 Be sure to fill out your full name and your 7 digit Cornell ID on the scantron sheet 3 Record answers to all multiple choice questions on the bubble sheet in pencil or pen and answers to short answer questions directly on the exam in pen Short answer questions not written in pen will not be eligible for re grading 4 Write legibly If we cannot read your answer we WILL NOT grade it 5 Use only the space provided Answers provided outside of space provided will not be graded 6 Do NOT use calculators or any other electronic devices 7 Write down the day and time your discussion section meets and circle the name of your TA Day and Time of your section Adam Bisogni Matt Lewis David Peck Adrian Powell Fahad Raza Glenn Stamps All multiple choice are worth 3 pts each and all short answers are worth 4 pts possible 67 points total Q14 Q15 Q16 Q17 Q18 Q19 Q20 SA MC 1 Downloaded by yelena radutskaya radutskaya yahoo com Total lOMoARcPSD 3454541 Name Multiple Choice 1 Which of the following is FALSE about neurons A Both Rm and Ri influence how fast the membrane potential changes after an injection of current B Most neurons transfer information to other neurons via chemical rather than electrical connections C Neurons convey information via manipulating the electrical properties of the postsynaptic cell D Most neurons only convey information in one direction E Neurotransmitter signaling is faster than hormone signaling 2 Which variable in the Goldman Equation which is absent from the Nernst Equation allows the Goldman Equation to predict the actual observed voltage of a membrane A Membrane capacitance B The membrane permeability of each ion C Ion independent membrane resistance D Axon diameter E Membrane ion channel orientation 3 You are recording from two neurons The physical properties of both neurons are identical with one exception Neuron 1 has twice the density of leaky K channels as Neuron 2 You inject a series of subthreshold pulses of positive current of the same amplitude into each neuron Assume both neurons exhibit temporal summation Based on the properties of the two neurons select the statement below that BEST describes what you would observe A Each current pulse will trigger a smaller change in membrane potential in Neuron 2 compared to Neuron 1 B The rate the membrane potential changes is the same for both neurons C The number of current pulses required to reach threshold will be greater for Neuron 1 D The threshold for triggering an action potential is higher in Neuron 2 E The electrical responses recorded in both neurons would be identical 4 You inject EDTA a compound that reduces the free Ca2 into the axon terminal of a neuron You then trigger an action potential in the neuron and measure the current in a postsynaptic neuron Assuming the postsynaptic response is excitatory which of the following is most likely to occur after the injection of EDTA A You will observe no change in the post synaptic response because there is very little free calcium in the cytoplasm of neurons at any given time B EPSPs will not be observed because the EDTA will block the voltage gated Ca2 channels in the pre synaptic neuron C EDTA will reduce Ca2 mediated release of neurotransmitters therefore reducing measured EPSPs D EDTA will reduce Ca2 mediated recycling of neurotransmitter catabolism and metabolism therefore reducing total neurotransmitter levels and measured EPSPs E Spatial summation will cease to occur and therefore no EPSPs will be measured 5 If the following 5 events in excitation contraction coupling at the neuromuscular junction were put into the proper temporal order which event would occur third A Depolarization of the sarcoplasmic reticulum B Ca2 binds to troponin C Release of acetylcholine from vesicles D Tropomyosin configuration changes E Myosin heads bind to F actin and ratchets 2 Downloaded by yelena radutskaya radutskaya yahoo com lOMoARcPSD 3454541 Name 6 If the toxin of a venomous snake bound to the Ca2 pumps of the sarcoplasmic reticulum such that they remained open what would happen to the muscle after stimulation A The muscle could contract normally B The muscle could not contract at all C The muscle could not stop contracting D The muscle could only contract a little bit E The muscle would go limp 7 In the patellar reflex circuit what role does the interneuron play A The interneuron inhibits the quadriceps muscle contralateral to the side of the stimulus B The interneuron excites the intrafusal fiber on the ipsilateral side of the stimulus C The interneuron inhibits the intrafusal fiber on the ipsilateral side of the stimulus D The interneuron inhibits the motor neuron for the antagonistic muscle ipsilateral to the side of the stimulus E The interneuron inhibits the antagonistic muscle ipsilateral to the side of the stimulus 8 You are on your way to a bakery but as you walk down the street you accidentally inhale gas from a construction site that contains a chemical that selectively inhibits adenylate cyclase in your olfactory sensory neurons You then walk into the bakery Which of the following most likely describes what will happen to your ability to smell the odorants of the bakery A You will not be able to smell the bakery odorants because adenylate cyclase is required to hydrolyze ATP to generate cAMP in the olfactory signal transduction pathway B You will be able to smell the odorants more strongly preventing adenylate cyclase from hydrolyzing ATP will prevent cAMP from inhibiting the activation of the cAMP gated Na Ca2 channels C You will not be able to smell the bakery odorants because inhibiting adenylate cyclase will prevent Golf the G protein linked to olfactory receptors from becoming activated D You will be able to smell the odorants more strongly Preventing adenylate cyclase activation will block the Cl channel making the olfactory sensory neuron more depolarized after odorants bind to olfactory receptors E None of the above