Free NEET Biology multiple-choice questions on Breathing and Respiration. Attempt each question and reveal the answer with a full explanation.
People living at sea level have around 5 million RBC per cubic millimeter of their blood whereas those living at an altitude of 5400 metres have around 8 million. This is because at high altitude- People get pollution-free air to breathe and more oxygen is available Atmospheric O2 level is less and hence more RBCs are needed to absorb the required amount of O2 to survive There is more UV radiation which enhances RBC production People eat more nutritive food, therefore more RBCs are formed The partial pressures (in mm Hg) of oxygen ( O 2 ) and carbon dioxide ( CO 2 ) at alveoli (the site of diffusion) are: pO 2 = 40 and pCO 2 = 45 pO 2 = 95 and pCO 2 = 40 pO 2 = 159 and pCO 2 = 0.3 pO 2 = 104 and pCO 2 = 40 Which of the following is not the function of conducting part of respiratory system? Inhaled air is humidified Temperature of inhaled air is brought to body temperature Provides surface for diffusion of O 2 and CO 2 It clears inhaled air from foreign particles Under normal physiological conditions in human being every 100 ml of oxygenated blood can deliver ml of O2 to the tissues. 5 ml 4 ml 10 ml 2 ml Vital capacity of lung is . (1) IRV + ERV (2) IRV + ERV + TV + RV (3) IRV + ERV + TV – RV (4) IRV + ERV + TV The solubility of CO 2 in blood is approximately how many times higher than that of O 2 ? 20-25 times 2-5 times 10-15 times 50 times What is the approximate percentage of CO 2 transported in the form of carbamino-haemoglobin? 20-25% 70% 7% 97% At the physiological pH, most of the CO 2 produced in the tissues is transported to the lungs as: Bicarbonate ions Dissolved gas in plasma Carbamino-haemoglobin Carbonic acid The 'Pneumotaxic Center', which can moderate the functions of the respiratory rhythm center, is located in which part of the brain? Pons varolii Medulla oblongata Cerebellum Hypothalamus What are the partial pressures of O 2 ( PO 2 ) and CO 2 ( PCO 2 ) in the atmospheric air (in mm Hg) compared to the alveolar air? PO 2 is 159, PCO 2 is 0.3 PO 2 is 104, PCO 2 is 40 PO 2 is 40, PCO 2 is 45 PO 2 is 95, PCO 2 is 40 What is the concentration of HCO 3 - (bicarbonate) in the blood compared to CO 2 dissolved in plasma? Approximately 70% of CO 2 is transported as HCO 3 - Approximately 20-25% of CO 2 is transported as HCO 3 - Approximately 7% of CO 2 is transported as HCO 3 - Approximately 97% of CO 2 is transported as HCO 3 - Name the chronic respiratory disorder caused mainly by cigarette smoking :- Emphysema Asthma Respiratory acidosis Respiratory alkalosis The enzyme 'Carbonic Anhydrase' is found in very high concentration in which of the following? Erythrocytes (RBCs) Lymphocytes Blood plasma Platelets The Eustachian tube is a canal that connects the middle ear cavity with which of the following? Pharynx Larynx External auditory canal Inner ear Which of the following is the most important buffer system in human blood plasma for maintaining acid-base balance? Bicarbonate-Carbonic acid system Phosphate buffer system Protein buffer system Hemoglobin buffer system To maintain electrical neutrality during the 'Chloride Shift' (Hamburger phenomenon), which of the following ions moves from the plasma into the erythrocytes? Cl - HCO 3 - K + Na + In the chemical regulation of respiration, the 'Chemosensitive area' located adjacent to the rhythm center is highly sensitive to which of the following? CO 2 and hydrogen ions O 2 and CO 2 levels Only O 2 levels Only HCO 3 - ions What is the role of 'Carbonic Anhydrase' in the transport of CO 2 in the blood? It facilitates the formation of H 2CO 3 from H 2O and CO 2 in RBCs It binds directly to CO 2 to form carbamino-haemoglobin It breaks down glucose into CO 2 It helps in the diffusion of CO 2 across the alveolar membrane Every 100 ,mL of deoxygenated blood delivers approximately how much CO 2 to the alveoli under normal physiological conditions? 4 ,mL 5 ,mL 10 ,mL 20 ,mL What are the partial pressures of oxygen ( PO 2 ) and carbon dioxide ( PCO 2 ) in deoxygenated blood, respectively? 40 ,mmHg and 45 ,mmHg 95 ,mmHg and 40 ,mmHg 40 ,mmHg and 40 ,mmHg 104 ,mmHg and 40 ,mmHg During the 'Chloride Shift' (Hamburger phenomenon) in tissues, chloride ions ( Cl - ) move from the plasma into the erythrocytes to balance the exit of: Bicarbonate ions ( HCO 3 - ) Hydrogen ions ( H + ) Potassium ions ( K + ) Sodium ions ( Na + ) The 'Bohr Effect' describes the decrease in the affinity of haemoglobin for oxygen in the presence of: High PCO 2 and low pH Low PCO 2 and high pH Low temperature High PO 2 Air pollution can result in Emphysema, which is Damage to any Lung tissue causing increase in elasticity of the air sacs Chronic damage to air sacs or alveoli leading to abnormal reduction in respiratory surface area Persistent inflammation and damage to the cells lining the bronchi and bronchioles An allergic reaction causing musclespasms in the bronchial walls Every 100 ,mL of oxygenated blood can deliver approximately how much oxygen ( O 2 ) to the tissues under normal physiological conditions? 5 ,mL 4 ,mL 20 ,mL 10 ,mL A shift to the right of the Oxygen-Haemoglobin dissociation curve is caused by which of the following factors? High pCO 2 High pO 2 Low H + concentration Low temperature What happens to the p50 value of the Oxygen-Haemoglobin dissociation curve during the Bohr effect? It increases It decreases It remains constant It becomes zero Which one of the following statements is incorrect ? (1) The residual air in lungs slightly decreases the efficiency of respiration in mammals (2) The presence of non-respiratory air sacs, increases the efficiency of respiration in birds (3) In insects, circulating body fluids serve to distribute oxygen to tissues (4) The principle of countercurrent flow facilitates efficient respiration in gills of fishes The figure shows a diagrammatic view of human respiratory system with labels A, B, C and D. Select the option which gives correct identification and main function and/or characteristic. A - trachea - long tube supported by complete cartilaginous rings for conducting inspired air B-pleural membrane - surround ribs on both sides to provide cushion against rubbing C-Alveoli - thin walled vascular bag like structures for exchange of gases D-Lower end of lungs - diaphragm pulls it down during inspiration Match the items given in Column I with those in Column II and select the correct option given below: a i, b iv, c ii, d iii a iii, b i, c iv, d ii a iii, b ii, c i, d iv a iv, b iii, c ii, d i Identify the wrong statement with reference to transport of oxygen Partial pressure of CO2 can interfere with O2 binding with haemoglobin Higher H + conc. in alveoli favours the formation of oxyhaemoglobin Low p CO2 in alveoli favours the formation of oxyhaemoglobin Binding of oxygen with haemoglobin is mainly related to partial pressure of O2 Select the favourable conditions required for the formation of oxyhaemoglobin at the alveoli. Low pO 2 , high pCO 2 , more H + , higher temperature High pO 2 , high pCO 2 , less H + , higher temperature Low pO 2 , low pCO 2 , more H + , higher temperature High pO 2 , low pCO 2 , less H + , lower temperature Match List I with List II : array ll List I & List II A. Expiratory capacity & I. Expiratory reserve volume + Tidal volume + Inspiratory reserve volume B. Functional residual capacity & II. Tidal volume + Expiratory reserve volume C. Vital capacity & III. Tidal volume + Inspiratory reserve volume D. Inspiratory capacity & IV. Expiratory reserve volume + Residual volume array Choose the correct answer from the options given below : A-II, B-IV, C-I, D-III A-III, B-II, C-IV, D-I A-II, B-I, C-IV, D-III A-I, B-III, C-II, D-IV Which of the following factors are favourable for the formation of oxyhaemoglobin in alveoli? High pO 2 and High pCO 2 High pO 2 and Lesser H+ concentration Low pCO 2 and High H+ concentration Low pCO 2 and High temperature Which of the following cannot be measured by spirometry ? Vital capacity Tidal volume Inspiratory reserve volume Residual volume In humans, respiration occurs in the following steps. Arrange these steps in the correct order. A. Diffusion of O2 and CO2 between blood and tissues B. Diffusion of O2 and CO2 across alveolar membrane C. Pulmonary ventilation by which atmospheric air is drawn in and CO2 rich alveolar air is released out D. Cellular respiration E. Transport of gases by the blood Choose the correct answer from the options given below A, B, C, D, E C, A, B, E, D C, B, E, A, D E, A, C, D, B Match List-I with List-II. array llll ; & List-I (Respiratory Volume) & ; & List-II (Capacity in mL) A. & ERV (Expiratory Reserve Volume) & I. & 2500 – 3000 mL B. & RV (Residual Volume) & II. & 500 mL C. & IRV (Inspiratory Reserve Volume) & III. & 1000 – 1100 mL D & TV (Tidal Volume) & IV. & 1100 – 1200 mL array Choose the correct answer from the options given below : A-III, B-IV, C-I, D-II A-III, B-I, C-IV, D-II A-I, B-II, C-III, D-IV A-I, B-III, C-II, D-IV Which of the following options correctly represents the lung conditions in asthma and emphysema, respectively? Increased respiratory surface; Inflammation of bronchioles Increased number of bronchioles; Increased respiratory surface Inflammation of bronchioles; Decreased respiratory surface Decreased respiratory surface; Inflammation of bronchioles Which of the following is an occupational respiratory disorder? Botulism Silicosis Anthracis Emphysema Due to increasing air-borne allergens and pollutants, many people in urban areas are suffering from respiratory disorder causing wheezing due to (1) reduction in the secretion of surfactants by pneumocytes. (2) benign growth on mucous lining of nasal cavity (3) inflammation of bronchi and bronchioles (4) proliferation of fibrous tissues and damage of the alveolar walls Tidal Volume and Expiratory Reserve Volume of an athlete is 500 mL and 1000 mL, respectively. What will be his Expiratory Capacity if the Residual Volume is 1200 mL? 2700 mL 1500 mL 1700 mL 2200 mL Select the correct events that occur during inspiration. (a) Contraction of diaphragm (b) Contraction of external inter-costal muscles (c) Pulmonary volume decreases (d) Intra pulmonary pressure increases (c) and (d) (a), (b) and (d) only (d) (a) and (b)