Respiration – structures, pigments, gas transport and regulation - Question Bank

1. Which of the following conditions would DECREASE the release of oxygen from hemoglobin to the tissues?
A) Increased temperature
B) Increased PCO2
C) Decreased pH
D) Increased PO2
2. The main function of the respiratory system is to facilitate:
A) Nutrient absorption
B) Waste excretion
C) Gas exchange
D) Hormone transport
3. The partial pressure of oxygen (PO2) in the tissues is typically around:
A) 100 mmHg
B) 40 mmHg
C) 95 mmHg
D) 159 mmHg
4. In which organism is respiration mediated by book lungs?
A) Grasshopper
B) Earthworm
C) Scorpion
D) Fish
5. The process of exhalation during normal, quiet breathing is primarily:
A) An active process involving muscle contraction
B) A passive process due to elastic recoil
C) Controlled by the diaphragm alone
D) Dependent on external intercostal muscles
6. Which of the following statements about hemoglobin is FALSE?
A) It is a protein found in red blood cells.
B) It binds to oxygen reversibly.
C) It transports most of the carbon dioxide in the blood.
D) It contains four polypeptide chains and four heme groups.
7. What is the role of the pons in respiratory regulation?
A) It contains the primary chemoreceptors
B) It modifies the rate and depth of breathing initiated by the medulla
C) It controls voluntary breathing
D) It detects changes in lung stretch
8. The structure that prevents food from entering the trachea is the:
A) Uvula
B) Epiglottis
C) Glottis
D) Cricoid cartilage
9. What is the approximate percentage of oxygen transported by hemoglobin in the blood?
A) 1.5%
B) 98.5%
C) 70%
D) 30%
10. The exchange of gases between the air in the alveoli and the blood in the pulmonary capillaries is called:
A) Internal respiration
B) Cellular respiration
C) Pulmonary ventilation
D) External respiration
11. Which of the following respiratory pigments has the lowest affinity for oxygen?
A) Hemoglobin
B) Myoglobin
C) Hemocyanin
D) Chlorocruorin
12. In mammals, the primary muscle involved in quiet inspiration is the:
A) External intercostals
B) Internal intercostals
C) Diaphragm
D) Abdominal muscles
13. The vocal cords are located within the:
A) Pharynx
B) Nasal cavity
C) Larynx
D) Trachea
14. What is the partial pressure of carbon dioxide (PCO2) in the alveoli?
A) About 100 mmHg
B) About 40 mmHg
C) About 45 mmHg
D) About 0.3 mmHg
15. Which part of the brain contains chemoreceptors that are sensitive to changes in blood CO2 and pH levels?
A) Cerebellum
B) Pons
C) Medulla oblongata
D) Olfactory bulb
16. The 'chloride shift' is a process associated with the transport of which gas in red blood cells?
A) Oxygen
B) Carbon dioxide
C) Nitrogen
D) Carbon monoxide
17. Hemerythrin is a respiratory pigment found in some marine invertebrates, which contains:
A) Copper
B) Iron
C) Magnesium
D) Manganese
18. The process of gas exchange between the blood and the body tissues is called:
A) External respiration
B) Internal respiration
C) Ventilation
D) Cellular respiration
19. Which group of animals typically uses cutaneous respiration (breathing through the skin)?
A) Mammals
B) Birds
C) Amphibians
D) Reptiles
20. When the partial pressure of CO2 in the blood increases, what happens to the affinity of hemoglobin for oxygen?
A) It increases
B) It decreases
C) It remains unchanged
D) It fluctuates unpredictably
21. What is the primary function of the nasal conchae?
A) To produce mucus
B) To humidify, warm, and filter inhaled air
C) To resonate voice sounds
D) To detect odors
22. The structure that connects the larynx to the bronchi is the:
A) Pharynx
B) Esophagus
C) Trachea
D) Bronchioles
23. Which of the following has the highest affinity for hemoglobin compared to oxygen?
A) Carbon dioxide
B) Carbon monoxide
C) Nitrogen
D) Bicarbonate
24. The process by which air moves into and out of the lungs is known as:
A) Diffusion
B) Gas exchange
C) Ventilation
D) Perfusion
25. The respiratory pigment in the blood of some annelids (like earthworms) is dissolved directly in the plasma and is called:
A) Hemoglobin
B) Hemocyanin
C) Chlorocruorin
D) Myoglobin
26. What is the primary role of the diaphragm during inspiration?
A) It relaxes and moves upward, decreasing thoracic volume
B) It contracts and moves downward, increasing thoracic volume
C) It remains stationary
D) It contracts and moves upward, decreasing thoracic volume
27. Which chamber of the human heart receives oxygenated blood from the lungs?
A) Right atrium
B) Right ventricle
C) Left atrium
D) Left ventricle
28. In terrestrial invertebrates like insects, gas exchange occurs through a system of tubes called:
A) Book lungs
B) Gills
C) Tracheae
D) Alveoli
29. The ' Haldane effect' describes the influence of oxygen levels on the transport of which gas?
A) Nitrogen
B) Carbon dioxide
C) Oxygen
D) Carbon monoxide
30. What is the partial pressure of oxygen (PO2) in the alveoli?
A) About 40 mmHg
B) About 100 mmHg
C) About 159 mmHg
D) About 0.3 mmHg
31. Myoglobin is a protein that stores oxygen primarily in which type of tissue?
A) Red blood cells
B) Liver cells
C) Muscle cells
D) Nerve cells
32. Which part of the respiratory system acts as a common passage for both food and air?
A) Nasal cavity
B) Larynx
C) Pharynx
D) Trachea
33. The enzyme responsible for catalyzing the formation of bicarbonate ions from carbon dioxide and water in red blood cells is called:
A) Catalase
B) Carbonic anhydrase
C) Hemoglobinase
D) Oxidase
34. What is the main stimulus that triggers an increase in breathing rate?
A) Low oxygen levels
B) High carbon dioxide levels
C) Low blood pressure
D) High body temperature
35. The process of breathing in is called:
A) Expiration
B) Inspiration
C) Respiration
D) Ventilation
36. Which respiratory pigment is found in the blood of some marine worms and contains iron, but is not contained within red blood cells?
A) Hemoglobin
B) Hemocyanin
C) Chlorocruorin
D) Myoglobin
37. The movement of gases across the respiratory membrane is driven by:
A) Active transport
B) Osmosis
C) Diffusion
D) Facilitated diffusion
38. In birds, the respiratory system is unique due to the presence of:
A) Diaphragm
B) Alveoli
C) Air sacs
D) Gills
39. Which of the following conditions leads to a decrease in hemoglobin's affinity for oxygen?
A) Increased pH
B) Decreased CO2 levels
C) Increased temperature
D) Increased PO2 in tissues
40. What is the role of surfactant in the alveoli?
A) To transport oxygen
B) To reduce surface tension and prevent alveolar collapse
C) To secrete mucus
D) To trigger coughing reflexes
41. The structure responsible for producing vocal sounds is the:
A) Pharynx
B) Larynx
C) Esophagus
D) Nasal cavity
42. Which law states that the volume of a gas is inversely proportional to its pressure at a constant temperature?
A) Dalton's Law
B) Henry's Law
C) Boyle's Law
D) Charles's Law
43. What is the primary mechanism by which carbon dioxide is transported in the blood?
A) Dissolved in plasma
B) Bound to hemoglobin
C) As bicarbonate ions
D) All of the above
44. In fish, gas exchange occurs across which specialized structures?
A) Lungs
B) Tracheae
C) Gills
D) Skin
45. The Bohr effect describes the influence of which factor on the oxygen-binding affinity of hemoglobin?
A) Temperature
B) pH
C) Carbon dioxide concentration
D) All of the above
46. Which respiratory pigment is found in the hemolymph of some arthropods and mollusks, and contains copper instead of iron?
A) Hemoglobin
B) Chlorocruorin
C) Hemerythrin
D) Hemocyanin
47. What is the partial pressure of oxygen (PO2) in deoxygenated blood entering the lungs?
A) About 100 mmHg
B) About 40 mmHg
C) About 159 mmHg
D) About 0.3 mmHg
48. The rate of breathing is primarily regulated by the respiratory center located in which part of the brain?
A) Cerebrum
B) Cerebellum
C) Medulla Oblongata
D) Hypothalamus
49. What is the main function of the epiglottis?
A) To produce sound
B) To filter air
C) To prevent food from entering the trachea
D) To warm inhaled air
50. In which part of the human respiratory system does gas exchange primarily occur?
A) Trachea
B) Bronchi
C) Alveoli
D) Larynx