BIOS 252 Final Exam Practice test Questions and Answers

BIOS 252 Final Exam Practice test Questions and Answers Which of the following is a recognized function of skeletal muscle? 1) A) guard body entrances and exits B) maintain posture C) maintain body temperature D) produce movement E) all of the above - Ans:-E Nerves and blood vessels that service the muscle fibers are located in the connective tissues of the A) myofibrils. B) sarcolemma. C) endomysium. ©GRACEAMELIA 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED FIRST PUBLISH OCTOBER 2024 Page 2/71 D) sarcomere. E) perimysium. - Ans:-E Which of the following best describes the term sarcoplasmic reticulum? A) largely made of myosin molecules B) storage and release site for calcium ions C) thin filaments are anchored here D) protein that accounts for elasticity of resting muscle E) repeating unit of striated myofibrils - Ans:-B Interactions between actin and myosin filaments of the sarcomere are responsible for A) the conduction of neural stimulation to the muscle fiber. B) muscle fatigue. C) the striped appearance of skeletal muscle. D) muscle contraction. E) muscle relaxation. - Ans:-D ©GRACEAMELIA 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED FIRST PUBLISH OCTOBER 2024 Page 3/71 The region of the sarcomere that always contains thin filaments is the A) Z line. B) A band. C) H band. D) M line. E) I band. - Ans:-E At rest, active sites on the actin are blocked by A) calcium ions. B) troponin molecules. C) tropomyosin molecules. D) myosin molecules. E) ATP molecules. - Ans:-C Cross-bridges are portions of A) actin molecules. ©GRACEAMELIA 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED FIRST PUBLISH OCTOBER 2024 Page 4/71 B) myosin molecules. C) tropomyosin molecules. D) troponin molecules. E) calcium ions. - Ans:-B When a skeletal muscle fiber contracts, A) the zones of overlap get larger. B) the H bands and I bands get smaller. C) the Z lines get closer together. D) the width of the A band remains constant. E) all of the above - Ans:-E The following is a list of the events that occur during a muscle contraction. 1. Myosin cross-bridges bind to the actin. 2. The free myosin head splits ATP. 3. Calcium ion is released from the sarcoplasmic reticulum. 4. The myosin head pivots toward the center of the sarcomere. 5. Calcium ion binds to troponin. 6. The myosin head binds an ATP molecule and detaches from the actin. The correct sequence of these events is ©GRACEAMELIA 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED FIRST PUBLISH OCTOBER 2024 Page 5/71 A) 3, 5, 1, 2, 4, 6. B) 1, 4, 6, 2, 3, 5. C) 1, 3, 5, 4, 6, 2. D) 5, 1, 4, 6, 2, 3. E) 3, 5, 1, 4, 6, 2. - Ans:-E Active sites on the actin become available for binding after A) troponin binds to tropomyosin. B) calcium binds to tropomyosin. C) myosin binds to troponin. D) calcium binds to troponin. E) actin binds to troponin. - Ans:-D In an isotonic contraction, A) muscle tension exceeds the load and the muscle lifts the load. B) many twitches fuse into one. C) tension rises and falls but the muscle length is constant. D) flexion is produced. E) the peak tension is less than the load. - Ans:-A ©GRACEAMELIA 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED FIRST PUBLISH OCTOBER 2024 Page 6/71 During anaerobic glycolysis A) oxygen is not consumed. B) pyruvic acid is produced. C) ATP is produced. D) all of the above E) B and C only - Ans:-D The type of muscle fiber that is most resistant to fatigue is the ________ fiber. A) intermediate B) fast C) high-density D) anaerobic E) slow - Ans:-E Shortening a muscle while it maintains constant tension is calle