BIOSC 0160 CRN 12336 PINK Foundations of Biology I Foundations of Biology I Fall Term 2010 Dr Laurel Roberts 3rd EXAMINATION Before filling in your name and PeopleSoft ID please check that the color of your scantron sheet matches the color of your test In column J of the scantron sheet blacken the circle corresponding to the color of your exam white 1 blue 2 pink 3 yellow 4 Proceed with the exam choosing the best answer for each of the following questions and blackening the proper circle on the answer sheet with a Number 2 pencil Read each question carefully before marking the best answer on your scantron sheet Work thoughtfully Make educated guesses if necessary Even wild guessing throughout should net you 20 of the total points on the average PLACE THE ANSWER SHEET IN ITS OWN COLOR PILE when you are done a b c b c a b 1 Which of the following statements about acetylcholine is false Acetylcholine is a neurotransmitter Acetylcholine is found at mammalian neuromuscular junctions Both smooth muscles and skeletal muscles respond to acetylcholine d Acetylcholine is degraded by acetylcholinesterase X e Acetylcholine increases contractility of the heart 2 Transport in the xylem is driven by a ATP hydrolysis b root pressure c guttation X d the evaporation of water from leaves e the cohesion of water 3 What is responsible for the absolute refractory period X a The de activation of voltage gated sodium channels The re activation of voltage gated sodium channels The de activation of voltage gated potassium channels d e The re activation of voltage gated potassium channels The inrush of calcium through voltage gated channels 4 In order from start to finish the basic steps of a signal transduction pathway are signal responder receptor effects receptor signal responder effects signal receptor responder effects X c d signal receiver responder effects e None of the above 5 Sucrose enters a plant cell through a sucrose proton symport If sucrose is added to a solution bathing a plant cell which of the following would probably occur a Extra cellular sucrose would not enter the cell b Photosynthesis would be inhibited X c The pH of the extracellular solution would increase d Residual cellular sucrose would leave the cell and enter the extracellular solution e The pH of the extracellular solution would decrease PINK Page 2 6 In shoot phototrophic responses auxin is transported and from the apical meristem X a down asymmetrically b down symmetrically c upward symmetrically d evenly toward the roots e upward toward the tip 7 Put the following events in relative order Not all numbers will be used 1 Voltage gated potassium channels open to allow the efflux of potassium 2 The voltage gated sodium channels are de activated which is characteristic of a absolute refractory period 3 A neurotransmitter binds to a receptor on the dendrite causing an action potential 4 Voltage gated sodium channels open to allow the efflux of sodium 5 The voltage gated potassium channels remain open to allow for a hyperpolarization beyond resting potential 6 The graded potential travels down to the axon hillock where it activates voltage gated ion channels a 3 6 4 1 2 5 b 3 6 1 2 5 X c 6 1 2 5 d 6 4 2 5 e 1 2 6 5 4 8 Stomata begin to open when K X a becomes concentrated water enters guard cells and the cells become turgid b c leaves guard cells and they become less turgid enters guard cells and they become less turgid 9 The sodium potassium pump a needs energy to work b moves potassium ions to the inside of a neuron and sodium ions to the outside c works against a concentration gradient d leaves guard cells and they become turgid e reaches equilibrium in guard cells and their surroundings d causes the axon to return to resting potential X e All of the above 10 Signals that travel to distant cells are known as a paracrine signals b parasitic signals c autocrine signals X d hormones e responders 11 The pressure flow model of translocation depends entirely on the existence of mechanisms for loading sugars into phloem at the regions and for unloading them at the regions a sink sink b sink source c source source X d source sink e source source or sink Page 3 PINK 12 Which of the following processes can take place even without the presence of living cells a Respiration X b Transpiration c Translocation X a ATP b the sun c NADPH d Active transport e Facilitated diffusion d bulk flow e chloroplasts 13 To drive water into root cells energy comes most directly from 14 Voltage gated sodium channels and voltage gated potassium channels activate At different times but open at the same time At the same time but open at different times X d At the same time and open at the same time e The timing depends on the position of the node on the axon a b c At different times but open at different times 15 Which process makes the water potential in a leaf more negative a The pressure placed on the leaf by the cuticle The increased K pumped out of guard cells d e The movement of water from the veins into the leaf X b The evaporation of water from mesophyll cells c The movement of water into the leaf by root pressure 16 If the Beta unit of a G protein were unable to bind GTP which of the following would occur a b c The Fight or Flight response would be inhibited Lithium would be useless as a treatment for bipolar disorder Smell and taste receptors would be inhibited d A B and C would all occur X e None of these A B C would occur 17 Animals use to set their internal clocks while plants use a cortisol brassinosteroid d somatostatin phytochrome b melatonin gibberellins c T3 T4 auxin X e None of these combinations is correct 18 Which of the following describes the resting potential of the neuronal cell membrane a The inside is 60 70 millivolts more positive than the outside X b The outside is 60 70 millivolts more positive than the inside c The inside is 30 35 millivolts more positive than the outside d e The outside is 30 35 millivolts more positive than the inside The inside has about the same charge as the outside 19 The mechanism by which ethylene works to alter gene transcription is PINK Page 4 X a Disinhibition the ligand binds to a receptor that inhibits an inhibitor b Disinhibition the ligand binds to a receptor that inhibits an activator c Feedforward inhibition the ligand binds to a receptor that inhibits an inhibitor 20 Second messengers a are typically very specific in their activity b do not amplify a signal c have enzymatic activity d e