Exam 2018, questions and answers PDF

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2016 to 2018 past exams with answers...

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2018 S1, 2017 S1 & S2 NOW IN DOC

BIOL1040 Cells to Organisms Past Exams Hello All! I hope studying is progressing well! :) We now have the following past exams in the doc: - 2018 S1 - 2017 S2 - 2017 S1 - For some reason, I couldn’t add the image to a short answer question - can anyone help me? - 2016 S1 Thank you :o) Add a +1 next to your multiple choice answer, if someone has voted before you add to the number i.e. +1 becomes +2 etc. HAPPY VOTING :) hi Please make comments on anything you disagree with and the reason. Thank you! This is so helpful! +2 Link to share with others: https://docs.google.com/document/d/1pQnNB-JM-Ka7lpde7MALmF5g20rt4FgTmxHkJzbNQA/edit?usp=sharing

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SECTION A – MULTIPLE CHOICE

2018 S1, 2017 S1 & S2 NOW IN DOC

Recommended time = 80 minutes Number of questions = 40 _______________________________________________ 1 Which of the following statements about the cell membrane and diffusion is CORRECT? [2 marks] A The central region of the cell membrane consists of hydrophilic fatty acids tails B Lipophilic molecules diffuse through the cell membrane more easily than lipophobic molecules +29 C Phospholipids in the cell membrane have a hydrophobic phosphate head +1 (Other way around)(The question is asking which is CORRECT) D Ions easily diffuse through the cell membrane because they are small +1 (Ions are hydrophilic so get repelled by hydrophobic lipids and can’t diffuse through) (The question is asking which is CORRECT) E Large hydrophobic molecules diffuse more quickly across the cell membrane than small hydrophobic molecules [41744]

Background for Q2 Consider the following solutions: I contains 150 mM KCl II contains 100 mM NaCl + 50 mM KCl III contains 100 mM NaCl + 200 mM of a small non-polar molecule IV contains only 200 mM of a small lipid soluble molecule 2 Comparing the tonicities of these solutions, which of the following statements is INCORRECT? [2 marks] A Solution III is hypertonic compared with Solution IV B Solution III is hypertonic compared with Solution I +19 Solution III has osmolarity=200 (nonpolar molecules don’t contribute) whereas solution I has osmolarity=300. Therefore, III is actually hypotonic to I C Solution IV is hypotonic compared with Solution I +5 This cannot be the answer because its correct. Solution IV has concentration of 0 Osmol as smallv lipid soluble molecule is the same thing as a small non-polar molecule. Hence 0 Osmols < 300 Osmol and hence solution IV is hypotonic to Sol 1 :) D Solution III is hypotonic compared with Solution II → I know the answer is not D) but can someone please explain why wouldn’t it be ?????? I have forgotten it II is 300mM (2 x 100 for NaCl and 2 x 50 for KCl) and III is 200mM (2 x 100 NaCl), small non polar molecules can cross the membrane so they don’t count, III is therefore hypotonic to II and D is correct E Solutions I and II are isotonic +1 - Why is this not the answer?? Because the question is asking for INCORRECT statements; Solutions I has 300 Osmol (150 x 2), and solution II also has 300 Osmol (100 x 2 for NaCl and 2 x 50 for KCl). Therefore since they are the same concentrations Solutions I and II are isotonic :)) [41681] Osmolarity = no.of solute particles x Molar Concentrations I. 150 x 2= 300 osmol/L II. 100 x 2 + 50 x 2 = 300 osmol/L III. Small, Polar molecules can pass through the membrane (Passive diffusion occurs) . = 200 Osmol/L

2018 S1, 2017 S1 & S2 NOW IN DOC IV.

Osmosis does not occur here

3 The membrane Na+/K+-ATPase of cells is responsible for solute transport by [2 marks] A active transport +23 B endocytosis C facilitated diffusion D passive diffusion E osmosis [47584]

4 Which of the following statements regarding proteins that form pores in the cell membrane is INCORRECT? [2 marks] A Transporter proteins are important for terminating the synaptic action of most neurotransmitters, including glutamate and dopamine +2 (Why is it not this???) B Transporters can mediate facilitated diffusion or active transport C Ion channels are specific such that a particular channel may allow facilitated diffusion of, for example, Na+ ions, but not K+ ions +2 D Voltage-gated Na+ channels allow active transport of Na+ ions out of cells to establish the negative membrane potential +20 why? voltage gated Na+ channels only allow passive transport (It says INCORRECT up top)a E Aquaporins allow facilitated diffusion of water across the cell membrane [39063]

5 Following a meal, insulin plays a key role in maintaining glucose homeostasis by activating cell surface insulin receptors. Mutations in the insulin receptor that prevent its phosphorylation of tyrosine residues would be expected to [2 marks] A enhance the translocation of glucose transporters to the cell surface, and thereby increase glycogen storage in the cell B enhance the translocation of glucose transporters to the cell surface, but have no effect on glycogen storage in the cell C enhance the translocation of glucose transporters to the cell surface, and thereby decrease glycogen storage in the cell +1 D prevent the translocation of glucose transporters to the cell surface, and thereby increase glycogen storage in the cell E prevent the translocation of glucose transporters to the cell surface, and thereby decrease glycogen storage in the cell +20 [32204] 6 It is a hot day and a plant wants to close its stomata to avoid excessive water loss. How will it do it? [2 marks] A by transporting Na+ out of the guard cells B by reducing the amount of water taken up by the roots C by transporting K+ out of the guard cells +17 D by increasing the pressure of surrounding cells + 2 Isn’t this the more correct option? Thy dont move out the pottassium do they? (see image below) E by actively pumping water into the cells [47994]

2018 S1, 2017 S1 & S2 NOW IN DOC

7 The light reactions of photosynthesis [2 marks] A convert light energy into CO 2 B produce ATP and NADPH +21 C are carried out in the cytosol D produce sugars as an energy source for the plant E can occur during the day and the night [47995]

8 The Casparian strip [2 marks] A seals leaves to make them impermeable to fluids and gases B blocks apoplastic transfer of minerals to the xylem tissue in the vascular cylinder +14 C yields secondary growth by producing additional vascular tissue D stops penetration of gases into the meristematic cells E controls the uptake of toxic minerals by the aerial parts of the plants [47996]

9 The direction of cell elongation in plants is controlled by [2 marks] A the orientation of cellulose microfibrils within the cell wall + 10 (Since its cell specific rather than whole plant?) B the direction of the light source C gravity +1 (Experiment from lecture slides showed plants would rather grow up than down towards a light source, because of gravity Yeah, but it’s definitely controlled by light too and the microfibrils need to be able to separate so the cell couldn’t elongate perpendicular to microfibril direction) D the orientation of the water pumps in the plasma membrane E the ratio between auxin and gibberellin hormones +1 its not this one cos giberelin is the hormone that’s in the seed that starts the germination process when in contact with water (signals the aleurone to release the amylase, that breaks down the starch into glucose, then used for growth) [47998]

10 During germination, the embryo receives nutrients from the seed by [2 marks] A producing sugars in the leaves by photosynthesis B releasing ATP from the aleurone cell layer

2018 S1, 2017 S1 & S2 NOW IN DOC

C dissolving sugars stored in the endosperm +4 (not this one, cos sugars are stored as glycogen, which won’t dissolve directly. It must be broken down by a-amylase first and gibberellin signals this) D absorbing nutrients from the root E releasing α-amylase from the aleurone layer as a consequence of gibberellin signalling +12 [47999]

Background for Q11 Adeline is working part-time as an assistant at a dental surgery, while she is studying at UQ. One day, Mr Tan comes to have a decaying tooth removed. When the dentist gets ready to give Mr Tan an injection of the local anaesthetic, lignocaine, Adeline thinks about what she learned at university about membrane potentials in nerves and how lignocaine works.

11 Which of the following statements about membrane potentials and lignocaine is CORRECT? [2 marks] A During the repolarisation phase of an action potential, voltage-gated K+ channels open and voltage-gated Na+ channels inactivate +19 B The pain nerves in the patient’s mouth have a positive resting membrane potential +2 (resting potential is always -70mV) C Lignocaine prevents the voltage-gated Na+ channels in the neurons from changing from the open to the inactivated state +3 (Lignocaine stops it going from inactive to closed state) D Lignocaine stimulates the activity of voltage-gated Na+ channels E Generation of action potentials in the pain nerves in Mr Tan’s mouth requires the opening of voltage-gated Cl- channels [47585]

12 The absolute refractory period in a neurone [2 marks] A allows the propagation of action potentials in both directions along an axon B is associated with the depolarisation phase of the action potential C is preceded by the relative refractory period D is when voltage-gated Na+ channels cannot be activated even with a large electrical stimulus +24 E occurs due to the opening of voltage-gated K+ channels [47586]

13 With regard to the sympathetic nervous system, which one of the following statements is INCORRECT? [2 marks] A Cell bodies of preganglionic sympathetic neurons are located in the sympathetic chain near the spinal cord B Sympathetic stimulation is responsible for increasing heart rate, opening of the airways and reduced intestinal activity C The sympathetic part of the autonomic nervous system is responsible for the so-called “fight or flight” response D Sympathetic pathways tend to have very long preganglionic neurons and short postganglionic neurons +13 E Sympathetic innervation leaves the spinal cord in the thoracic and lumbar regions [47587]

14 Which of the following statements about white and grey matter in the central nervous system

2018 S1, 2017 S1 & S2 NOW IN DOC

is CORRECT? [2 marks] A Grey matter contains neuronal cell bodies, whereas white matter contains myelinated axons +17 B White matter within the spinal cord is organised into horns, whereas grey matter is organised into tracts C White matter is myelinated by Schwann cells, whereas grey matter is myelinated by oligodendrocytes D White matter is found in the cerebral cortex, whereas grey matter is found deeper within the brain E Grey matter in found at the periphery of the spinal cord, whereas white matter is found centrally in the spinal cord [44934]

15 Which of the following is an INCORRECT association of function with the named region of the brain? [2 marks] A The selectivity filter that determines arousal and sleep with the reticular formation in the cerebral cortex +13 (this is correct. It is literally the definition of the reticular formation given in the lecture slides) (it’s in the brain stem though, not cerebral cortex) - Yall dumb mofos lmao lol B Communication between the right and left hemispheres of the cerebral cortex with the corpus callosum C Movement with the basal nuclei where nerves degenerate in patients with Parkinson’s disease +6 D Memory with the hippocampus and cerebral cortex E Emotions with several areas of the brain that are collectively referred to as the limbic system [39066]

16 Clench your fists into a tight ball, and then open your fingers so that they are straight. As you straighten your fingers, you are [2 marks] A extending +21 B adducting +1 (This is moving to another body part or the midline of your body) C abducting D flexing E rotating [47614]

17 Which of the following statements about human skeletal muscle is INCORRECT? [2 marks] A The endomysium lies deep within the muscle, surrounding each muscle fibre B Sarcomere length can influence the amount of passive force within a musculotendinous structure +4 (I would say this is correct as the sarcomeres are what is holding the muscle together thus influencing passive force, C is more incorrect) C A sarcomere is very long, and each sarcomere is multinucleated +16 (muscle fibres are multinucleated, but sarcomeres are not. Also, sarcomeres are relatively short and only the cell itself is long, so this answer is very incorrect!) D Sarcomere length influences the amount of active force that can be generated E The greatest predictor of muscle force is the Physiological Cross Sectional Area of the muscle [47617]

2018 S1, 2017 S1 & S2 NOW IN DOC

18 Which of the following statements about a contracting muscle is INCORRECT? [2 marks] A Myosin and titin bind to shorten the muscle during the power stroke +23 B ‘Contractility’ refers to the ability of the muscle to shorten and thicken, and develop tension C Eccentric contractions can produce more force than concentric contractions D ‘Excitability’ refers to the ability of muscle to respond to the appropriate stimuli E When the muscle shortens, the Z-lines of the sarcomeres are pulled closer together [47618]

19 In negative pressure ventilation, [2 marks] A exhalation occurs when our diaphragm contracts B air flows into our lungs when we build up a raised pressure inside our nasal passages, such as when we sneeze C the rib cage expands when our rib muscles contract +14 D inhalation occurs when pressure in our chest is higher than atmospheric pressure E elastic recoil of the lung tends to increase lung volume [41677]

Background for Q20 and Q21 Jonah gets extremely stressed just before he enters the room for a recent examination and starts hyperventilating. In hyperventilation, there is an increased rate and force of breathing, resulting in decreased blood CO2 levels. 20 Which of the following will occur as a result of this hyperventilation? [2 marks] A The pH of the blood will decrease +1 (...