IB Biology Problem Set Unit I Physiology Topics 6.1, 6.2, 6.4, 6.5, 11.2 1. What happens during muscle contraction? A. The number of light bands is reduced. B. The width of the dark bands is reduced. C. The lengths of the sarcomeres are reduced. D. Actin and myosin filaments coil up. 2. What is indicated by the letters X, Y and Z? Name X Y Z A. sarcomere myosin filaments actin filaments B. sarcomere actin filaments myosin filaments C. dark band myosin filaments actin filaments D. dark band actin filaments myosin filaments 3. Which is the sequence of events in muscle contraction? I. Use of ATP II. Formation of cross bridges III. Release of calcium ions from the sarcoplasmic reticulum IV. Actin filament moves towards the centre of the sarcomere A. I II III IV B. III II IV I C. IV I II III D. II IV I III 4. What are the names of the two structures labelled I and II in the arm joint diagram below? I II A. biceps radius B. biceps humerus C. triceps humerus D. triceps ulna IB Questionbank Biology 1
5. What are the names of the organs labelled I and II in the diagram below? I II A. pancreas liver B. small intestine large intestine C. gall bladder pancreas D. esophagus stomach 6. The diagram below shows water in the human body. Where in the digestive system is the largest volume of water absorbed from? A. Colon B. Pancreas C. Small intestine D. Liver IB Questionbank Biology 2
7. Which of the following parts of the digestive system secrete proteases? Stomach Small Intestine Large Intestine A. Yes Yes Yes B. Yes No Yes C. Yes No No D. No No No 8. William Harvey discovered that blood flows away from the heart in arteries and back to the heart in veins. What hypothesis could be developed from this discovery? A. The human body contains both arteries and veins. B. Blood vessels link up arteries to veins. C. How blood moves from arteries into veins. D. Veins are connected to the left side of the heart and arteries to the right side. 9. Which of the following describes arteries? A. They have thick muscular walls. B. They usually contain valves. C. They carry blood towards the heart. D. They carry blood from the lungs. 10. Which chamber of the heart has the thickest walls? A. Left atrium B. Right atrium C. Left ventricle D. Right ventricle 11. Is the blood in the aorta, left ventricle and pulmonary artery oxygenated or deoxygenated? Aorta Left ventricle Pulmonary artery A. oxygenated deoxygenated deoxygenated B. deoxygenated oxygenated oxygenated C. oxygenated oxygenated deoxygenated D. oxygenated oxygenated oxygenated 12. What causes air to be breathed out by the lungs? A. The diaphragm relaxes and the ribs fall. B. The ribs rise and the external intercostal muscles relax. C. The internal intercostal muscles contract and the ribs rise. D. The diaphragm contracts and internal intercostal muscles contract. 13. What normally prevents the membranes of the alveoli from sticking together during expiration? A. The thickness of the single-cell layer of alveoli membranes B. The secretion of fluids in the inner surface of the alveoli C. The pressure within the thoracic cavity D. The dense net of capillaries covering the alveoli 14. Which muscles contract to cause air to pass out from the lungs through the bronchioles? A. Internal intercostal muscles and diaphragm B. Internal intercostal muscles and abdomen wall muscles C. External intercostal muscles and diaphragm D. External intercostal muscles and abdomen wall muscles IB Questionbank Biology 3
15. On the diagram of the motor neurone shown below, which label identifies a dendrite? 16. The diagram below shows the changes in membrane potential during an action potential. What occurs at the stages labelled 1 and 2? A. B. C. D. Na + ions diffuse in; inside becomes more positive K + ions diffuse out; inside becomes more negative Na + ions diffuse out; inside becomes more negative Na + ions diffuse in; inside becomes more positive 1 2 K + ions diffuse out; inside becomes more negative Na + ions diffuse in; inside becomes more positive K + ions diffuse out; inside becomes more positive K + ions diffuse in; inside becomes more negative 17. A process occurs in which the inside of a neuron develops a net positive charge compared with the outside. What is the name of this process? A. Resting potential B. Repolarization C. Depolarization D. Hyperpolarization IB Questionbank Biology 4
18. In the diagram of synaptic transmission below, what is indicated by the letters X and Y? [Source: http://en.wikipedia.org/wiki/file:synapse_illustration2_tweaked.svg. Image by Nrets.] X A. neurotransmitter enters synaptic knob Ca 2+ ions B. Ca 2+ ions diffuse into the synaptic knob neurotransmitter C. K + ions diffuse into the synaptic knob neurotransmitter D. Na + ions diffuse into the synaptic knob Ca 2+ ions 19. (a) Outline the functions of the (i) synovial fluid... (ii) joint capsule... Y (b) State the name of the structure that links muscle to bone. (c) Describe the role of calcium in muscle contraction. (2) (Total 5 marks) IB Questionbank Biology 5
20. Backflow is the return of blood to the heart. In legs, backflow is enhanced by the pumping action of leg muscles during movement. When this does not occur efficiently, serious health problems can arise. The backflow speed of 40 patients was measured during the application of different therapy methods. The lying position is the control. [Source: Adapted from postdoctoral thesis of Erich Meyer, Medical Faculty of the University of Erlangen-Nürnberg.] (a) (i) State which activity reduces backflow speed in relation to the control.... (b) (c) (ii) Suggest a reason why backflow speed is reduced by the activity stated in (a)(i).... Determine the difference in backflow speed between the lying position and pedal exercise.. Discuss the benefits of exercising to promote high backflow speed........ (3) (Total 6 marks) IB Questionbank Biology 6
21. As intensity of exercise increases, humans respond to the increased need for gas exchange in two ways: varying ventilation rate and varying tidal volume. Experimental data for a runner on a treadmill are shown below. 80 2.8 Tidal volume 70 2.6 2.4 Ventilation rate Ventilation rate / min 1 60 50 40 2.2 2.0 1.8 1.6 Tidal Volume / litres 30 1.4 1.2 20 7.50 9.00 10.50 12.00 13.50 15.00 16.50 18.00 1.0 Treadmill speed / km h 1 [Source: www.home.hia.no/~stephens/ventphys.htm] (a) Outline the relationship between treadmill speed and tidal volume. (b) (i) up to 14 km h 1...... (ii) above 14 km h 1...... Compare the trend in ventilation rate with the trend in tidal volume at a high treadmill speed. (c) Calculate the total volume of air inhaled per minute when the treadmill speed is 15 km h 1. (2) IB Questionbank Biology 7
22. (d) Suggest how the ventilation rate and tidal volume might alter if treadmill speed were increased even further. (2) (Total 7 marks) IB Questionbank Biology 8
23. From an early stage in human development, blood flow is needed for transport and exchange of materials. (a) (b) (c) Explain the exchange of gases in the alveoli of the lungs. Outline how William Harvey changed the understanding of blood flow around the human body. Describe how, in microscopic images, blood vessels can be identified as arteries, capillaries and veins. [8] [4] [3] 24. The human body need to be able to respond to the external environment around it. (a) Outline the process leading to the depolarization of a neuron, beginning from a signal reaching the terminal end of a presynaptic neuron. [8] (b) Describe how the villus is able to aid in the digestion of materials. [3] (c) Explain how the structure of a striated muscle cell aids in muscular contraction. [4] IB Questionbank Biology 9
IB Questionbank Biology 10