Bio 202 Spring 2019 Exam 2 Citovsky PDF

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Practice test Exam 2...

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Thur. March 14, 2019

Professor Vitaly Citovsky BIO 202.03 - MIDTERM EXAMINATION 2 Spring, 2019 Fill in your SCANTRON sheet as directed below. Do not forget to blacken the circles

ON YOUR SCANTRON: · • Enter your NAME at the top, last name first • DO NOT FILL IN YOUR BIRTHDATE • Enter your Stony Brook ID# in the LOWER LEFT HAND CORNER • In the WHITE MARGIN of the TOP LEFT of your scantron print the FIRST THREE WORDS of Question #1 • In the WHITE MARGIN of the TOP RIGHT, SIGN YOUR NAME DO NOT MARK ANY OTHER SPACES (except answers) on the SCANTRON QUESTIONS There are 10 pages with 50 exam questions including this cover page PENCIL Please use only a soft No. 2 Pencil CHECK Make SURE you have all pages of the exam and all 50 questions so you can check the key. ANSWERS MARK YOUR ANSWERS IN THIS TEST BOOKLET so you can check the key. The Scantrons will not be returned

1) Which structure is NOT part of the endomembrane system? A) nuclear envelope *B) chloroplast C) Golgi apparatus D) plasma membrane 2) The liver is involved in detoxification of many poisons and drugs. Which of the following structures is primarily involved in this process and, therefore, abundant in liver cells? A) rough ER *B) smooth ER C) Golgi apparatus D) nuclear envelope 3) Where are proteins produced other than on ribosomes free in the cytosol or ribosomes attached to the ER? A) in the extracellular matrix B) in the Golgi apparatus *C) in mitochondria D) in the nucleolus 4) Ions can travel directly from the cytoplasm of one animal cell to the cytoplasm of an adjacent cell through _____. A) plasmodesmata B) tight junctions C) desmosomes *D) gap junctions 5) The fluid mosaic model of the membrane proposed that membranes_____. A) are a phospholipid bilayer between two layers of hydrophilic proteins B) are a single layer of phospholipids and proteins *C) consist of protein molecules embedded in a fluid bilayer of phospholipids D) consist of a mosaic of polysaccharides and proteins 6) In what way do the membranes of a eukaryotic cell vary? A) Phospholipids are found only in certain membranes. *B) Certain proteins are unique to each membrane. C) Only certain membranes of the cell are selectively permeable. D) Some membranes have hydrophobic surfaces exposed to the cytoplasm, while others have hydrophilic surfaces facing the cytoplasm. 7) Diffusion _____. A) is very rapid over long distances B) requires an expenditure of energy by the cell *C) is a passive process in which molecules move from a region of higher concentration to a region of lower concentration D) requires integral proteins in the cell membrane

8) A signaling pathway begins with A) Binding of a second messenger to its receptor B) Binding of a cAMP molecule to its receptor C) Activation of G protein *D) Binding of a hormone molecule to its receptor 9) Celery stalks that are immersed in fresh water for several hours become stiff. Similar stalks left in a 0.15 M salt solution become limp. From this we can deduce that the fresh water_____. A) and the salt solution are both hypertonic to the cells of the celery stalks *B) is hypotonic and the salt solution is hypertonic to the cells of the celery stalks C) is hypertonic and the salt solution is hypotonic to the cells of the celery stalks D) is isotonic and the salt solution is hypertonic to the cells of the celery stalks 10) What will happen to a red blood cell (RBC), which has an internal ion concentration of about 150 mM, if it is placed into a beaker of pure water? A) The cell would shrink because the water in the beaker is hypotonic relative to the cytoplasm of the RBC. B) The cell would shrink because the water in the beaker is hypertonic relative to the cytoplasm of the RBC. *C) The cell would swell because the water in the beaker is hypotonic relative to the cytoplasm of the RBC. D) The cell will remain the same size because the solution outside the cell is isotonic. 11) Which of the following statements correctly describes the normal tonicity conditions for typical plant and animal cells? The animal cell is in _____. A) a hypotonic solution, and the plant cell is in an isotonic solution B) an isotonic solution, and the plant cell is in a hypertonic solution C) a hypertonic solution, and the plant cell is in an isotonic solution *D) an isotonic solution, and the plant cell is in a hypotonic solution 12) A sodium-potassium pump _____. A) moves three potassium ions out of a cell and two sodium ions into a cell while producing an ATP for each cycle *B) move three sodium ions out of a cell and two potassium ions into a cell while consuming an ATP for each cycle C) moves three potassium ions out of a cell and two sodium ions into a cell while consuming 2 ATP in each cycle D) move three sodium ions out of a cell and two potassium ions into a cell and generates an ATP in each cycle 13) An organism with a cell wall would most likely be unable to take in materials through _____. A) osmosis B) active transport *C) phagocytosis D) facilitated diffusion

14) When molecules move out of the cell by active transport A) cells use more ATP and less oxygen B) cells use less ATP and less oxygen *C) cells use more ATP and more oxygen D) cells use less ATP and more oxygen 15) In receptor-mediated endocytosis, receptor molecules initially project to the outside of the cell. Where do they end up after endocytosis? A) on the outside of vesicles B) on the inside surface of the cell membrane *C) on the inside surface of the vesicle D) on the outer surface of the nucleus 16) A bacterium engulfed by a white blood cell will be digested by enzymes contained in _____. *A) lysosomes B) Golgi vesicles C) vacuoles D) secretory vesicles 17) Myosin is a ______ and associates with _________ *A) molecular motor, microfilaments B) molecular motor, microtubules C) microfilament, dynein D) microfilament, flagellum 18) When oxygen is released as a result of photosynthesis, it is a direct by-product of _____. *A) splitting water molecules B) chemiosmosis C) the electron transfer system of photosystem I D) the electron transfer system of photosystem II 19) Tunneling nanotubes (TNTs) A) are found in plant cells and transport large molecules *B) are found in animal cells and transport large molecules C) are found in plant cells and transport small molecules D) are found in animal cells and transport small molecules 20) Suppose a plant has a unique photosynthetic pigment and the leaves of this plant appear to be reddish yellow. What wavelengths of visible light are absorbed by this pigment? A) red and yellow *B) blue and violet C) green and yellow D) blue, green, and red 21) Muscle cells in oxygen deprivation produce ______ and convert _______ to ______ a

*A) ATP, pyruvate, lactate B) ATP, glucose, lactate C) ATP, pyruvate, alcohol and CO2 D) ATP, glucose, alcohol and CO2 22) As electrons are passed through the system of electron carriers associated with photosystem II, they lose energy. What happens to this energy? A) It excites electrons of the reaction center of photosystem I. B) It is lost as heat. *C) It is used to establish and maintain a proton gradient. D) It is used to phosphorylate NAD+ to NADPH, the molecule that accepts electrons from photosystem I. 23) The final electron acceptor associated with photosystem I is _____. A) oxygen B) water *C) NADP D) NADPH 24) In the thylakoid membranes, the pigment molecules in a light-harvesting complex _____. A) split water and release oxygen from the reaction-center chlorophyll *B) absorb and transfer light energy to the reaction-center chlorophyll C) synthesize ATP from ADP and inorganic phosphate D) transfer electrons to ferredoxin and then NADPH 25) What are the products of non-cyclic electron flow? A) heat and fluorescence B) ATP and P700 *C) ATP and NADPH D) ADP and NADP+ 26) Assume a thylakoid is somehow punctured so that the interior of the thylakoid is no longer separated from the stroma. This damage will most directly affect the _____. A) splitting of water B) flow of electrons from photosystem II to photosystem I *C) synthesis of ATP D) reduction of NADP+ 27) In mitochondria, chemiosmosis moves protons from the matrix into the intermembrane space, whereas in chloroplasts, chemiosmosis moves protons from the _____. A) matrix to the stroma *B) stroma to the thylakoid space C) intermembrane space to the matrix D) thylakoid space to the stroma 28) Which of the following statements best describes the relationship between photosynthesis

and respiration? A) Respiration runs the biochemical pathways of photosynthesis in reverse. *B) Photosynthesis stores energy in complex organic molecules; respiration releases energy from complex organic molecules C) Photosynthesis occurs only in plants; respiration occurs only in animals. D) Photosynthesis is catabolic; respiration is anabolic. 29) Carbon dioxide is split to form oxygen gas and carbon compounds _____. A) during photosynthesis B) during respiration C) during photosynthesis and respiration *D) in neither photosynthesis nor respiration 30) Which of the following will lead specifically to defects in movement of sperm cells? A) mutation in a gene encoding actin B) mutation in a gene encoding myosin *C) mutation in a gene encoding tubulin D) mutation in a gene encoding spermin 31) In a plant, the reactions that produce molecular oxygen (O2) take place in _____. *A) the light reactions alone B) the Calvin cycle alone C) the light reactions and the Calvin cycle D) neither the light reactions nor the Calvin cycle 32) Cholesterol makes biological membranes more fluid at lower temperatures because it *A) restricts close packing of phospholipids B) promotes movement of phospholipids C) facilitates close packing of phospholipids D) enriches the membrane with unsaturated phospholipids 33) The solutions in the two arms of a U-tube are separated by a membrane that is permeable to water and glucose, but not to sucrose. Side A is filled with a solution of 2 M sucrose and 5 M glucose, and side B is filled with a solution of 2 M sucrose and 0.5 M of glucose. After the system reaches equilibrium, the levels of water on each side of the tube will be *A) the same B) side A higher than side B C) side B higher than side A D) B or C, depending on temperature 34) Which of the following are products of the light reactions of photosynthesis that are utilized in the Calvin cycle? A) CO2 and glucose B) H2O and O2 C) ADP, inorganic phosphate, and NADP+ *D) ATP and NADPH

35) An organic molecule can only slowly diffuse through artificial phospholipid bilayers, but the same molecule can diffuse rapidly into living cells. What would be your hypothesis about the most likely mechanism by which cells allow rapid influx of this molecule? A) active diffusion B) receptor-mediated endocytosis *C) facilitated diffusion D) active transport 36) What is the primary function of the Calvin cycle? A) use NADPH to release carbon dioxide B) split water and release oxygen C) transport RuBP out of the chloroplast *D) synthesize simple sugars from carbon dioxide 37) Which enzyme in the cell is primarily responsible for inactivating cAMP? A) cAMPase B) adenylyl cyclase C) hydrolase *D) phosphodiesterase 38) Which of the following sequences correctly represents the flow of electrons during photosynthesis? A) NADPH → O2 → C O2 *B) H2O → NADPH → Calvin cycle C) NADPH → chlorophyll → Calvin cycle D) NADPH → electron transport chain → O2 39) cAMP A) is produced by adenylyl cyclase from AMP *B) is produced by adenylyl cyclase from ATP C) is produced by phosphodiesterase from ATP D) is produced by phosphodiesterase from AMP 40) What compound provides the reducing power for Calvin cycle reactions? A) ATP B) NADH C) NADP+ *D) NADPH 41) Substrate-level phosphorylation occurs _____. A) in glycolysis B) in the Krebs cycle *C) in both glycolysis and the Krebs cycle D) during oxidative phosphorylation

42) The receptors for steroid hormones are located inside the cell instead of on the membrane surface like most other signal receptors. This is not a problem for cells because _____. A) the receptors can be readily stimulated to exit and relocate on the membrane surface B) steroids do not directly affect cells but instead alter the chemistry of blood plasma *C) steroid hormones are lipid soluble, so they can readily diffuse through the lipid bilayer of the cell membrane D) steroids must first bond to a steroid activator, forming a complex that then binds to the cell surface 43) Not all intercellular signals require a transduction pathway. Which one of the following signals could be processed without transduction pathway? *A) a lipid-soluble signal B) a signal that is weakly bound to a nucleotide C) a signal that binds to a receptor in the cell membrane D) a signal that binds to the ECM 44) Protein phosphorylation is commonly involved with all of the following EXCEPT _____. A) regulation of transcription by extracellular signaling molecules B) enzyme activation *C) activation of G protein-coupled receptors D) activation of protein kinase molecules 45) In general, a signal transmitted via phosphorylation of a series of proteins _____. *A) results in a conformational change to each protein B) requires binding of a hormone to an intracellular receptor C) activates a transcription event D) generates ATP in the process of signal transduction 46) Which of the following would most likely be an immediate result of a growth factor binding to its receptor? *A) protein kinase activity B) adenylyl cyclase activity C) protein phosphatase activity D) phosphorylase activity 47) Which of the following statements is true of signal molecules? A) When signal molecules bind to receptor tyrosine kinases, the receptors first phosphorylate a number of nearby molecules. B) In response to some G protein-mediated signals, a special type of lipid molecule associated with the plasma membrane is cleaved to form calcium. C) In most cases, signal molecules interact with the cell at the plasma membrane, enter the cell, and eventually enter the nucleus. *D) Protein kinase A activation is one possible result of signal molecules binding to G proteincoupled receptors. 48) Protein kinase is an enzyme that can _____.

A) function as a second messenger molecule B) serves as a signal for various receptor molecules *C) activate or inactivate other proteins by adding a phosphate group to them D) produce second messenger molecules 49) Which of the following amino acids are most frequently phosphorylated by protein kinases in the cytoplasm during signal transduction? A) methionine B) glycine and histidine *C) serine and threonine D) glycine and glutamic acid 50) Phosphorylation cascades involving a series of protein kinases are useful for cellular signal transduction because they _____. A) are species specific B) always lead to the same cellular response *C) amplify the original signal many times D) counter the harmful effects of phosphatases...