Online Ch 26 PDF

a condition known as “the bends.” It is thought that diving mammals avoid this condition by means of alveolar collapse, but this is an area that requires further research. Textbook Reference: Decompression Sickness Bloom’s Category: 2. Understanding 10. Discuss advantages and disadvantages of seque...

a condition known as “the bends.” It is thought that diving mammals avoid this condition by means of alveolar collapse, but this is an area that requires further research. Textbook Reference: Decompression Sickness Bloom’s Category: 2. Understanding 10. Discuss advantages and disadvantages of sequestering O2 in the lungs during a deep dive. Answer: The disadvantage of an animal’s sequestering O2 in the lungs during a deep dive is that it cannot be used as an O2 source during the dive. However, researchers have postulated two possible advantages for sequestration. First, the physiological mechanism of alveolar collapse causes the diffusion of nitrogen to be slowed or stopped, preventing the possibility of decompression sickness upon the animal’s ascent. Second, deep dives require a long period of ascent, which requires the use of oxygen. During the ascent, the alveoli open and can slowly resume diffusion. This pulmonary O2 can be used as an O2 source during the long ascent. Textbook Reference: A Possible Advantage for Pulmonary O2 Sequestration in Deep Dives Bloom’s Category: 5. Evaluating ONLINE QUIZ QUESTIONS 1. Dives by Weddell seals are mostly a. short and shallow. b. long and deep. c. short and deep. d. long and shallow. Answer: a Textbook Reference: Diving Feats and Behavior Bloom’s Category: 1. Remembering 2. The deepest dives of Weddell seals are at a depth of about _______ m. a. 300 b. 600 c. 900 d. 1,500 Answer: b Textbook Reference: Diving Feats and Behavior Bloom’s Category: 1. Remembering 3. Which animal is the deepest diver? a. Weddell seal b. Fur seal c. Elephant seal d. Crabeater seal © 2016 Sinauer Associates, Inc. Answer: c Textbook Reference: Diving Feats and Behavior Bloom’s Category: 5. Evaluating 4. An animal’s maximum possible blood store of O2 is calculated by a. multiplying the oxygen-carrying capacity of the blood by blood volume and then dividing by oxygen solubility. b. dividing the oxygen-carrying capacity of the blood by blood volume. c. multiplying the oxygen-carrying capacity of the blood by blood volume. d. multiplying the oxygen-carrying capacity of the blood by blood volume and multiplying that product by animal mass. Answer: c Textbook Reference: The Oxygen Stores of Divers Bloom’s Category: 3. Applying 5. One the most consistent features of diving species of mammals is that, relative to terrestrial species, they have a. very high myoglobin concentration in their skeletal muscle. b. very high myoglobin concentrations in their visceral organs. c. very high hemoglobin concentrations. d. high blood volumes. Answer: a Textbook Reference: The Oxygen Stores of Divers Bloom’s Category: 2. Understanding 6. In diving mammals, the thorax a. is rigid in order to prevent compression during dives. b. can be either rigid or compressible during dives, depending on the species. c. only compresses at depths beyond 1500 m. d. is freely compressible during dives. Answer: d Textbook Reference: The Oxygen Stores of Divers Bloom’s Category: 2. Understanding 7. Which oxygen store (per kg) is significantly larger in true (phocid) seals, such as the Weddell seal, compared to a human? a. O2 bound to myoglobin b. O2 bound to hemoglobin c. O2 in the lungs d. O2 bound to myoglobin and O2 bound to hemoglobin Answer: d Textbook Reference: The Oxygen Stores of Divers Bloom’s Category: 5. Evaluating 8. Which oxygen storage compartment tends to be the largest in diving mammals? a. Lungs © 2016 Sinauer Associates, Inc. b. Myoglobin c. Blood d. Interstitial fluids Answer: c Textbook Reference: The Oxygen Stores of Divers Bloom’s Category: 5. Evaluating 9. The predicted dive time of a Weddell seal based on calculations of its oxygen stores is likely to be _______ the actual maximal dive times measured in the field. a. shorter than b. longer than c. about the same length as d. exactly half Answer: a Textbook Reference: The Oxygen Stores of Divers Bloom’s Category: 2. Understanding 10. Which statement regarding circulation and diving is false? a. Regional vasoconstriction occurs during a forced dive. b. During an episode of regional vasoconstriction, flow to parts of the brain is cut off or severely restricted. c. Regional vasoconstriction occurs during a prolonged dive. d. During an episode of regional vasoconstriction, flow to parts of the body posterior to the heart is cut off or severely restricted. Answer: b Textbook Reference: Circulatory Adjustments during Dives Bloom’s Category: 5. Evaluating 11. Because of a regional vasoconstriction during a prolonged dive, the heart responds with a reduction in a. pressure. b. cardiac output. c. heart rate. d. cardiac output and heart rate. Answer: d Textbook Reference: Circulatory Adjustments during Dives Bloom’s Category: 2. Understanding 12. In freely diving marine mammals, heart rate a. does not change with dive duration. b. increases in a graded manner with dive duration. c. decreases immediately after a dive and then becomes independent of dive duration. d. decreases in a graded manner with dive duration. Answer: d Textbook Reference: Circulatory Adjustments during Dives Bloom’s Category: 2. Understanding © 2016 Sinauer Associates, Inc. 13. Fish removed from water are likely to exhibit a. slight bradycardia. b. profound bradycardia. c. slight tachycardia. d. profound tachycardia. Answer: b Textbook Reference: Circulatory Adjustments during Dives Bloom’s Category: 1. Remembering 14. During forced submergence, harbor seals deplete O2 in their _______, while O2 levels in their _______ remain high. a. lungs; blood b. blood; muscles c. muscles; blood d. lungs; muscles Answer: c Textbook Reference: Metabolism during Dives Bloom’s Category: 2. Understanding 15. Following a 45-minute dive by a Weddell seal, circulating levels of lactic acid would likely fall to pre-dive levels after about a. 20 minutes. b. 70 minutes. c. 2 hours. d. 4 hours. Answer: b Textbook Reference: Metabolism during Dives Bloom’s Category: 1. Remembering 16. Metabolic limits on dive duration are determined by all of the following except a. O2 stores. b. rates of O2 use. c. lactic acid production. d. lactic acid clearance. Answer: d Textbook Reference: Metabolism during Dives Bloom’s Category: 5. Evaluating 17. During a voluntary dive, a Weddell seal’s metabolic rate is _______ that of a resting seal on land. a. higher than b. lower than c. similar to d. extremely variable compared to Answer: b © 2016 Sinauer Associates, Inc. Textbook Reference: Metabolism during Dives Bloom’s Category: 2. Understanding 18. During a dive, blood pH tends to _______ due to an increase in _______. a. increase; lactic acid b. increase; CO2 and lactic acid c. decrease; CO2 and lactic acid d. decrease; lactic acid Answer: c Textbook Reference: Metabolism during Dives Bloom’s Category: 2. Understanding 19. The longest dive that can be undertaken without a net accumulation of lactic acid above resting level is called the a. aerobic dive limit. b. anaerobic threshold. c. anaerobic diving limit. d. aerobic dive scope. Answer: a Textbook Reference: The Aerobic Dive Limit: One of Physiology’s Key Benchmarks for Understanding Diving Behavior Bloom’s Category: 1. Remembering 20. What is the primary cause of decompression sickness? a. An imbalance of CO2 caused by surfacing too quickly b. Distention of lung tissue from rapid loss of pressure c. Formation of O2 bubbles in the blood d. Formation of N2 bubbles in the blood Answer: d Textbook Reference: Decompression Sickness Bloom’s Category: 2. Understanding © 2016 Sinauer Associates, Inc.