proctored exam (animal physiology)
Microsoft Word - midterm #2 2019 shortened BIO 3302 Animal Physiology II - Midterm #2 KM Gilmour NAME: _________________________________ November 25th, 2019 80 min STUDENT #: ____________________________ Cellular phones, unauthorized electronic devices or course notes (unless an open-book exam) are not allowed during this exam. Phones and devices must be turned off and put away in your bag. Do not keep them in your possession, such as in your pockets. If caught with such a device or document, the following may occur: academic fraud allegations will be filed which may result in you obtaining a 0 (zero) for the exam. By signing below, you acknowledge that you have ensured that you are complying with the above statement. SIGNATURE: _________________________________ Part A: Answer the following questions in the space provided on the question sheet. (1 mark per answer unless otherwise stated; 24 marks in total) 1. The hyperventilation experienced by a human at high altitude is stimulated by a fall in blood PO2 that is detected by type I (glomus) cells located in the carotid body. It results in an acid-base disturbance best described as a respiratory OR metabolic (select one) acidosis OR alkalosis (select one). 2. Compensation for a metabolic acidosis is a challenge to ionic homeostasis in a marine teleost such as the clownfish because… a. Sea water is more highly buffered than fresh water, reducing the effectiveness of the acid- trapping mechanism. b. Fish cannot afford to hypoventilate because O2 uptake would be compromised. c. Acid excretion in exchange for Na+ uptake by gill ionocytes adds to the salt load the fish must excrete. d. Marine teleost fish lack a rectal gland to excrete excess NaCl. e. All of the above explain why compensation for a metabolic acidosis is a challenge to ionic homeostasis in a marine teleost. 2 4. The cell in the figure at right illustrates a suite of structural characteristics that is often found in cells specialised for the function of _______________________________________. a. Identify two of these structural characteristics and in each case explain its functional significance. (2 marks) b. Assume that this cell was found in the salt-secreting gland of the Galapagos marine iguana, and add to the diagram above the three key membrane proteins expected to be found in a salt- secreting cell. (3 marks) 5. The figure at right presents the main inorganic and organic solutes in the extracellular fluids of three water- breathing vertebrates. Which bar (A, B or C) represents an osmoconformer that ionoregulates? ____________ The animal represented by which bar (A, B or C) would experience water loss to the surrounding environment? ____________ O sm ol ar ity (m O sm ol L- 1 ) 0 200 400 600 800 1000 1200 Na+ Cl- Other cations Other anions urea methylamines sea wa ter A B C 3 7. The sketch at right illustrates the pressures that drive glomerular filtration. a. Calculate the hydrostatic pressure gradient (show your calculation): b. Which pressure is controlled by autoregulatory mechanisms? ___________ 8. Xenopus (the African clawed frog) is an exception to the rule that adult amphibians are ammonotelic OR ureotelic OR uricotelic (select one) because it remains fully aquatic as an adult and therefore excretes ammonia OR urea OR uric acid (select one). 9. The sketch at right illustrates a mammalian nephron and nephrons found in teleost fish from marine and freshwater environments. a. Explain the functional significance of the structural difference between nephrons B and C. (2 marks) b. Explain the functional significance of the structural difference between nephrons A and D. (2 marks) 4 Part B: Answer the following questions in the exam booklet. (19 marks in total) 1. List two structural adaptations for life in a desert that are displayed by the kangaroo rat, and explain (BRIEFLY) the functional significance of each. (4 marks) 2. A group of (fictional) BIO 3302 students decided to investigate the effects of several solutions on kidney function. Urine flow rate (UFR), urine pH and urine osmotic concentration were measured following consumption of 500 mL of water, 2% NaCl, lemonade or beer. The data collected 1 h after consumption of the test solution are presented below together with “control” data for a student that drank water only when thirsty. Which student drank 500 mL of water, and what is the main hormonal response responsible for adjusting kidney function in this student? Please explain your reasoning. (5 marks) Name UFR (mL h-1 kg-1) Urine pH (pH units) Urine osmotic concentration (mmol kg-1) Opah Winfrey 0.3 6.7 880 Brad Pike 2.5 5.0 400 Angelfish Jolie 2.5 6.9 400 Carpi B 4.0 7.0 250 Control 1.2 6.8 540 Microsoft Word - midterm #2 2017 BIO 3302 Animal Physiology II - Midterm #2 NAME: _________________________________ November 23rd, 2017 80 min STUDENT #: ____________________________ Cellular phones, unauthorized electronic devices or course notes (unless an open-book exam) are not allowed during this exam. Phones and devices must be turned off and put away in your bag. Do not keep them in your possession, such as in your pockets. If caught with such a device or document, the following may occur: academic fraud allegations will be filed which may result in you obtaining a 0 (zero) for the exam. By signing below, you acknowledge that you have ensured that you are complying with the above statement. SIGNATURE: _________________________________ Part A: Answer the following questions in the space provided on the question sheet. (1 mark per answer unless otherwise stated; 23 marks in total) 1. Minor fluctuations in filtrate flow are detected by the ____________________________________ which signals to the ______________________________________________ to release vasoactive compounds that act on the afferent arteriole to adjust glomerular blood pressure and hence filtration. 2. The Magadi tilapia is an unusual teleost fish because… a. It retains ammonia as the end-product of nitrogen metabolism even when it emerges from water. b. It is a facultative ureotele that excretes urea across the gill in discrete pulses that occur about once in every 24-h period. c. It is an obligate ureotele that cannot excrete ammonia because of the high pH of the water in which it lives. d. It accumulates high levels of urea and the counter-balancing solute TMAO as an osmoregulatory strategy to prevent water loss in its marine environment. e. It excretes uric acid. 3. An increase in which of the following will decrease urinary Na+ loss? a. Circulating angiotensinogen levels b. Circulating aldosterone levels c. Circulating ADH levels d. Circulating atrial natriuretic peptide (ANP) levels e. Increases in all of the above cause urinary Na+ loss to decrease 2 5. Mammals are more resistant to water loss than amphibians. List two structural features that contribute to this difference, and briefly explain their significance. (4 marks) 6. Active NaCl excretion by the ________________________________________________ of the Galapagos marine iguana is an example of a regulated OR obligatory (select one) exchange. 7. On the axes at right, sketch the relationship between body fluid osmolarity and the osmolarity of the external environment for the brine shrimp, Artemia. (1 mark) In seawater, this animal is best described as a (select one) euryhaline OR stenohaline (select one) hyperosmotic OR iso-osmotic OR hypo- osmotic (select one) regulator OR conformer. Bo dy fl ui ds o sm ol ar ity (m O sm ol L- 1 ) 0 15001000500 Environmental osmolarity (mOsmol L-1) 0 1500 1000 500 Iso-osmotic line 3 9. True OR false (select one): Exposure of rainbow trout to hyperoxic (high O2) water causes a respiratory alkalosis. a. Justify your answer. b. The activity of what cell type in the gill would increase to correct the acid-base disturbance? 10. You drink three large pints of beer in rapid succession. Which one of the following best describes the renal response that will occur? a. No change in urine flow rate or osmolarity. b. Decreased production of urine; the urine is more concentrated than normal. c. Increased production of dilute urine. d. Decreased production of urine; the urine is highly acidic. e. Increased production of urine of normal osmolarity. Which one of the following best describes the hormonal response to beer consumption; this hormonal response results in the above renal response? a. Increased ADH levels in conjunction with a fall in aldosterone levels. b. The concentration of atrial natriuretic peptide (ANP) increased. c. No change in any of ADH, aldosterone or ANP levels. d. The ADH concentration fell. e. Increased ADH levels in conjunction with an increase in angiotensin II levels. 4 Part B: Answer the following questions in the exam booklet. (20 marks in total) 1. Sam the sockeye salmon spent his first year of life in a freshwater stream. He is now ready to move into the ocean but must first go through ‘smoltification’, the physiological transition from a freshwater teleost to a marine teleost. Explain the physiological changes that occur, using your knowledge of the ionoregulatory and osmoregulatory challenges faced by teleost fish in freshwater versus marine environments and the strategies they use to overcome these challenges. (8 marks) 2. Structure and function are often intimately linked in physiological systems, i.e. structures may be uniquely adapted to carry out particular functions, or the function of a particular system is made possible by its structure. Discuss such structure-function relationships with respect to the filtration mechanism of the vertebrate kidney. (6 marks)