lOMoARcPSD 3454541 Exam 18 May 2014 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 Final Exam BioG 1440 Total pages in exam including cover WATCH YOUR TIME This is a 60 minute test Name Student ID By signing below I acknowledge that I am abiding by Cornell University s Code of Academic Integrity Signature PLEASE 1 WRITE YOUR NAME on all pages of the exam 2 Record your answers to all multiple choice true false and matching questions directly on the exam 3 Write legibly If we cannot read your answer we cannot grade it 4 Use only the space provided 5 Do NOT use calculators or any other electronic devices Multiple choice 30 pts Short answer 40 pts Total Score out of 70 1 Downloaded by yelena radutskaya radutskaya yahoo com lOMoARcPSD 3454541 MULTIPLE CHOICE 3 points each For each of the following questions please choose the SINGLE BEST answer 1 Which feature of epithelia cells allows them to act a selective barrier a Tight Junctions form between the individual cells b The surface of epithelia is covered by the basement membrane that is selectively permeable to ions c Glycoproteins embedded in the membrane serve as a barrier to the diffusion of polar ions d Facilitated transport allows them to move molecules up their concentration gradients e Both a and e are correct 2 Which of the following portions of your vasculature has the largest total cross sectional area a aorta b arteries c arterioles d capillaries 3 Which statement concerning the allosteric regulation of enzymes is false a The binding of an activator positive regulator can stabilize the active form of an enzyme b Allosteric regulators can directly compete with the substrate to bind at the active site c Allosteric regulators can alter the enzymes affinity for its substrate d The effect of an allosteric regulator can be concentration dependent e Allosteric regulators bind reversible to their enzyme targets 4 Kidneys are amazing organs but they can t solve all our problems of homeostatsis in water salt physiology Which of the following cannot they do a b c d regulate plasma ion composition by selectively removing ions regulate plasma volume by adding water and removing ions simultaneously regulate plasma osmotic pressure by removing water and ions simultaneously actually they can do all of the above 5 Which of the following structure s is a source of signal molecules that regulate the release of hormones from the anterior pituitary a The posterior pituitary b The adrenal cortex c The gonads d The hypothalamus e All of the above 2 Downloaded by yelena radutskaya radutskaya yahoo com lOMoARcPSD 3454541 6 Living animals produce heat during which of the following forms of physiological work a b c d e skeletal muscle activity e g lifting weights biosynthetic activities e g synthesizing proteins maintenance functions e g moving ions across a membrane all of the above only a and c 7 The Bohr Effect Shift refers to a b c d e an increase in Na resorption by the collecting tubules of amphibian kidney an increase in the blood s capacity to buffer CO2 when deoxygenated a decline in hemoglobin s affinity for O2 with increasing concentration of CO2 an increase in hemoglobin s affinity for O2 with increasing concentration of CO2 an increase in the secretion of Aldosterone 8 All of the following are responses to glucocorticoids except a b c d e muscle protein catabolism increases insulin production increases T cell production decreases fat tissue catabolism increases all of the above are responses to glucocorticoids 9 Which of the following strategies is are used to transport O2 and CO2 in the mammalian circulatory system a Hemoglobin increases the bloods capacity to carry CO2 by buffering H b Myoglobin s affinity for O2 is higher than Hemoglobin s affinity for O2 c At the lung countercurrent gas exchange is used to increase efficiency of the exchange of O2 and CO2 d Both b and c are correct e All three statements are correct 10 Which of the following would result in an increase in the length constant of an axon a b c d e Decreasing the axon s internal diameter Increasing the membrane capacitance Increasing the axon s internal diameter Increasing the membranes resting K permeability Both b and c are correct 3 Downloaded by yelena radutskaya radutskaya yahoo com lOMoARcPSD 3454541 SHORT ANSWERS Using PEN write your answers in the space provided below observing sentence and space limits Think about your answer before you begin writing 4 points each 11 During an action potential the depolarization of the membrane is due to the inward flow of Na ions while outward flow of K ions is responsible for repolarizing the membrane You are able to increase the internal concentration of Na from 15mM to 30mM What effect will this have on a on the height of the overshoot increase x decrease no change Explain your answer Increasing the internl concentration of Na will reduce the Na Equilibrium potential This will reduce Na s driving force resulting in a lower overshoot b on the size of the undershoot after hyperpolarization increase decrease X no change Explain your answer The size of the after hyperpolarization is primarily determined by the membranes permeability to K 4 Downloaded by yelena radutskaya radutskaya yahoo com lOMoARcPSD 3454541 12 Given that your heart s stroke volume is about 80 milliters when you are resting and given that the total volume of the blood in your body is about 5 liters how long does it take to pump all your blood once through your body in your current resting physiological state Show your calculation 80 ml stroke x 60 strokes min 4800 ml min Hence it takes only about one minute to pump all your blood once through your body 13 A friend is recovering from a rather serious biking accident He recently learned that gamma neurons that innervate the intrafusal muscle fibers of his bicep were severed Your friend is curious to learn what a gamma motor does and how this might injury might affect his daily trip to the gym to lift weights What can you tell your friend Your friend will have problems controlling the movements of their arm The gamma motor neuron is responsible for shortening the intrafusal fibers This will mean that he will not sense the load on their arm as they lift an object When lifting a familiar object she should experience few problems However if