MCQ Questions Chapter 17 Breathing and Exchange of Gases Class 11 Biology

Please refer to MCQ Questions Chapter 17 Breathing and Exchange of Gases Class 11 Biology with answers provided below. These multiple-choice questions have been developed based on the latest NCERT book for class 11 Biology issued for the current academic year. We have provided MCQ Questions for Class 11 Biology for all chapters on our website. Students should learn the objective based questions for Chapter 17 Breathing and Exchange of Gases in Class 11 Biology provided below to get more marks in exams.

Chapter 17 Breathing and Exchange of Gases MCQ Questions

Please refer to the following Chapter 17 Breathing and Exchange of Gases MCQ Questions Class 11 Biology with solutions for all important topics in the chapter.

MCQ Questions Answers for Chapter 17 Breathing and Exchange of Gases Class 11 Biology

Question- Which of the following conditions is responsible for increase in ventilation rate of lungs ?
(a) Increase of CO₂ content in inhaled air.
(b) Increase of CO₂ content in exhaled air.
(c) Decrease in O₂ content of inhaled air.
(d) Decrease in O₂ content of exhaled air.

Question- Oxyhaemoglobin dissociates into oxygen and deoxyhaemoglobin at
(a) low O₂ pressure in tissue.
(b) high O₂ pressure in tissue.
(c) equal O₂ pressure inside and outside tissue.
(d) all times irrespective of O₂ pressure.

Question- When CO₂ concentration in blood increases, breathing becomes
(a) slow and deep.
(b) faster and deeper.
(c) shallower and slow.
(d) there is no effect on breathing.

Question- Air travels through
(i) Nose (ii) Skin
(iii) Trachea (iv) Mouth
(a) Both (i) and (ii)
(b) Both (i) and (iv)
(c) only (i)
(d) only (ii)

Question- During oxygen transport the oxyhaemoglobin at the tissue level liberates oxygen to the cells because in tissue 
(a) O₂ concentration is high and CO₂ is low
(b) O₂ concentration is low and CO₂ is high
(c) O₂ tension is high and CO₂ tension is low
(d) O₂ tension is low and CO₂ tension is high

Question- Read the following statements and select the correct option.
(i) Carbonic anhydrase is present in the erythrocytes .
(ii) In erythrocytes the carbon dioxide combine with water and is transported.
(a) Statement (i) is correct and is responsible for statement (ii).
(b) Statement (i) is not correct but statement (ii) is correct.
(c) Both statement (i) and (ii) are incorrect.
(d) Statement (i) is correct but not involved in statement (ii).

Question- The presence of CO₂ in blood will lower pH because CO₂ combines with____, with the rate of reaction increased by_____ . 
(a) H₂O to form H+ and HCO₃^–, carbonic anhydrase
(b) H₂O to form only HCO₃^–, carbonic anhydrase
(c) H₂O to form only H⁺, carbonic ions
(d) H⁺ to form HCO₃ ^–, oxyhaemoglobin

Question- Which one of the followings statements is not correct?
(a) Total volume of air a person can expire after a normal inspiration is called expiratory capacity.
(b) Binding of oxygen with haemoglobin is primarily related to partial pressure of CO₂.
(c) Every 100 ml of deoxygenated blood delivers approximately 4 ml of CO₂ to the alveoli.
(d) Every 100 ml of oxygenated blood can deliver around 5 ml of O₂ to the tissues under normal physiological conditions.

Question-Which of the following match is correct?
(a) Emphysema: reduction of surface area ofM alveoli and bronchi
(b) Pneumonia: occupational disease with asbestos
(c) Silicosis: inflammation of alveoli
(d) Asthma: excessive secretion of bronchial mucus

Question- Listed below are four respiratory capacities (A-D) in column I and four jumbled respiratory volume of a normal human adult in column II.
Column -I                                          Column-II
(Respiratory capacities)                  (Respiratory volumes)
A. Residual volume                              I. 2500 mL
B. Vital capacity                                  II. 3500 mL
C. Inspiratory reserve volume            III. 1200 mL
D. Inspiratory capacity                        IV. 4500 mL
Which one of the following is the correct matching of two capacities and volume?
(a) A – I; B – II; C – III; D – IV.
(b) A – IV; B – III; C – I; D – II.
(c) A – II; B – III; C – IV; D – I.
(d) A – III; B – IV; C – I; D – II.

Question- Volume of air breathed in and out during normal breathing is called 
(a) Vital capacity
(b) IRV
(c) ERV
(d) Tidal volume

Question- Match the column I (Organs) with column II (Functions) and choose the correct option.
Column – I                   Column – II
(Organs)                     (Functions)
A. Nose                     I. Stops food from going down into lungs.
B. Epiglottis              II. Produces sound.
C. Pharynx               III. Traps bacteria as well as dust.
D. Larynx                 IV. Allows air to pass from nose to oesophagus.
(a) A – II; B – III; C – I; D – IV
(b) A – III; B – I; C – IV; D – II
(c) A – I; B – IV; C – II; D – III
(d) A – IV; B – II; C – III; D – I

Question- Match the disorders given in column – I with symptoms under column – II. Choose the answer which gives the correct combination.
Column-I                    Column-II
(Disorders)                   (Symptoms)
A. Asthma             I. Inflammation of nasal tract
B. Bronchitis         II. Spasm of bronchial muscles
C. Rhinitis             III. Fully blown out alveoli
D. Emphysema      IV. Inflammation of bronchi
                               V. Cough with blood strained sputum
(a) A – IV; B – II; C – V; D – I
(b) A – V; B – III; C – II; D – I
(c) A – III; B – I; C – V; D – IV
(d) A – II; B – IV; C – I; D – III

Question- About 70% of CO₂ is transported as
(a) carbonic acid
(b) darboxyhaemoglobin
(c) bicarbonates
(d) carbamino compounds

Question- Approximately seventy percent of carbondioxide absorbed by the blood will be transported to the lungs
(a) as bicarbonate ions
(b) in the form of dissolved gas molecules
(c) by binding to RBC
(d) as carbamino – haemoglobin

Question- Match the column I (Animals) with column II (Mode of respiration) and choose the correct option.
Column – I                  Column – II
(Animals)                 (Mode of respiration)
A. Earthworm          I. Pulmonary
B. Human                II. Branchial
C. Prawn                 III. Tracheal
D. Insects               IV. Cutaneous
(a) A – I; B – II; C – III; D – IV
(b) A – IV; B – II; C – I; D – III
(c) A – IV; B – I; C – II; D – III
(d) A – III; B – II; C – IV; D – I

Question- Dissociation curve shifts to the right when
(a) pH increases.
(b) CO₂ concentration increases.
(c) O2 concentration decreases.
(d) 2, 3 D-P-G decreases.

Question- Which one of the following four organs of respiratory system is correctly matched with its characteristics?
A. Bronchi – Two branches of the trachea that brings air into the lungs.
B. Trachea – Small flap that prevents food from entering
C. Diaphragm – Dome shaped muscle that pushes on the lungs during exhalation.
D. Alveoli – Pair of organs that inflate as you inhale and deflate as you exhale.
(a) A and B only
(b) C and D only
(c) A and C only
(d) B and D only

Question- During oxygen transport, the oxyhaemoglobin at the tissue level liberates oxygen to the cells because in tissue
(a) O₂ concentration is high and CO₂ is low.
(b) O₂ concentration is low and CO₂ is high.
(c) O₂ tension is high and CO₂ tension is low.
(d) O₂ tension is low and CO₂ tension is high.

Question- What would happen if human blood becomes acidic (low pH)?
(a) Oxygen carying capacity of haemoglobin increases.
(b) Oxygen carrying capacity of haemoglobin decreases.
(c) RBCs count increases.
(d) RBCs count decreases.

Question- Functional residual capacity in human is the amount of air
(a) that can be filled in lungs by forceful inspiration.
(b) that can be breathed out after forceful expiration.
(c) that remains in the lungs after normal expiration.
(d) that remains in the lungs after forceful expiration.

Question- In humans, the concentration of carbon dioxide in the plasma 
(a) causes increased production of hydrochloric acid.
(b) regulates gastric acid production by forming carbonic acid.
(c) regulates breathing rate by its effect on the medulla.
(d) causes inflammation of the tissues of the bronchial tubes.

Question- When, under certain conditions, the P50 value of haemoglobin rises, the affinity of the pigment of combining with O₂ will
(a) remain same
(b) rise
(c) fall
(d) first rise and then fall

Question- Even when there is no air in it, human trachea does not collapse due to presence of
(a) bony rings
(b) turgid pressure
(c) chitinous rings
(d) cartilaginous rings

Question- Arrange the following events in the correct order as they occur during inspiration:
I. Air flows into the lungs.
II. Alveolar volume increases.
III. Thoracic volume increases.
IV. Pleural pressure decreases.
V. Alveolar pressure decreases.
(a) I – II – III – IV – V
(b) III – IV – II – V – I
(c) II – V – I – III – IV
(d) IV – V – II – I – III

Question- Which of the following are the stages of respiration in correct order?
A – Gaseous transport B – Cellular respiration
C – Tissue respiration D – Breathing
(a) A – D – C – B
(b) D – A – C – B
(c) D – A – B – C
(d) D – C – B – A

Question- If the respiratory rate of ‘A’ is 35 breaths/min and tidal volume 185 cc/breath and of ‘B’ is 25 breaths/min and tidal volume 259 cc/breath then
(a) Pulmonary ventilation of ‘A’ and ‘B’ is same.
(b) Alveolar ventilation of ‘A’ and ‘B’ is same.
(c) Pulmonary ventilation of ‘A’ is greater than ‘B’.
(d) Alveolar ventilation of ‘A’ is greater than ‘B’.

Question- If a person is suffering from emphysema, his/her
(a) bronchioles are found damaged.
(b) alveolar walls are found damaged.
(c) the plasma membrane is found damaged.
(d) the respiratory muscle is found damaged.

Question- Which of the following statements are true/false?
(i) The blood transports CO₂ comparatively easily because of its higher solubility.
(ii) Approximately 8 -.9% of CO₂ is transported being dissolved in the plasma of blood.
(iii) The carbon dioxide produced by the tissues, diffuses passively into the blood stream and passes into red blood corpuscles and react with water to form H₂CO₃
(iv) The oxyhaemoglobin (HbO₂) of the erythrocytes is basic.
(v) The chloride ions diffuse from plasma into the erythrocytes to maintain ionic balance.
(a) (i), (iii) and (v) are true; (ii) and (iv) are false.
(b) (i), (iii) and (v) are false; (ii) and (iv) are true.
(c) (i), (ii), and (iv) are true; (iii) and (v) are false.
(d) (i), (ii) and (iv) are false; (iii) and (v) are true.

Question- Blood analysis of a patient reveals an unusually high quantity of carboxyhaemoglobin content. Which of the following conclusions is most likely to be correct? The patient has been inhaling polluted air containing usually high content of
(a) chloroform
(b) carbon dioxide
(c) carbon monoxide
(d) carbon disulphide

Question- Common feature in the alveoli of lungs and villi of intestine in mammals is that both
(a) provide a large surface area.
(b) have ciliated epithelium.
(c) are suited for diffusion of gases.
(d) have rich supply of blood vessels and lymph ducts.

Question- Low oxygen tension in the blood causes
(a) coughing
(b) yawning
(c) hiccuping
(d) sneezing

Question- After taking a long deep breath, we do not respire for some seconds due to
(a) more CO₂ in blood
(b) more O₂ in blood
(c) less CO₂ in blood
(d) less O₂ in blood

Question- A large proportion of oxygen is left unused in the human blood even after its uptake by the body tissues. This O₂
(a) helps in releasing more O₂ to the epithelium tissues.
(b) acts as a reserve during muscular exercise.
(c) raises the pCO₂ of blood to 75 mm of Hg.
(d) is enough to keep oxyhaemoglobin saturation at 96%.

Question- Which one of the following is a possibility for most of us in regard to breathing, by making a conscious effort?
(a) One can consciously breathe in and breathe out by moving the diaphragm alone, without moving the ribs at all.
(b) The lungs can be made fully empty by forcefully breathing out all air from them.
(c) One can breathe out air totally without oxygen.
(d) One can breathe out air through Eustachian tubes by closing both the nose and the mouth.

Question- The urge to inhale in humans results from
(a) rising pCO₂
(b) rising pO₂
(c) falling pCO₂
(d) falling pO₂

Question- External gills, tracheae, and lungs all share which of the following sets of characteristics ?
(a) Part of gas-exchange system, exchange both CO₂ and O₂; increase surface area for diffusion.
(b) Used by water breathers; based on countercurrent exchange; use negative pressure breathing.
(c) Exchange only O₂; are associated with a circulatory system; found in vertebrates.
(d) Found in insects; employ positive-pressure pumping based on crosscurrent flow.

Question- Oxidative breakdown of respiratory substrates with the help of O₂ is called as 
(a) fermentation
(b) anaerobic respiration
(c) R. Q.
(d) aerobic respiration

Question- What happens during breathing?
(i) Size of our chest increases.
(ii) Size of our chest decreases.
(iii) Carbon dioxide is removed out from body.
(iv) Air enters our lungs.
(a) (i) and (ii)
(b) (i) and (iv)
(c) (ii) and (iii)
(d) (ii) and (iv)

Question- Severe Acute Respiratory Syndrome (SARS)
(a) is caused by a variant of Pneumococcus pneumoniae. 
(b) is caused by a variant of the common cold virus (corona virus).
(c) is an acute form of asthma.
(d) affects non-vegetarians much faster than the vegetarians.

Question- Presence of large number of alveoli around alveolar ducts opening into bronchioles in mammalian lungs is
(a) inefficient system of ventilation with little of residual air.
(b) inefficient system of ventilation with high percentage of residual air.
(c) an efficient system of ventilation with no residual air.
(d) an efficient system of ventilation with little residual air.

Question- Number of RBCs per unit volume of blood is likely to be higher in a person living at high altitudes, because
(a) air is clean and unpolluted.
(b) more sunshine is available.
(c) air is less dense.
(d) vegetation gives out more O₂.

Question- Oxyhaemoglobin can transport 
(a) 8 ml of CO₂/100 ml blood
(b) 5 ml of CO₂/100 ml blood
(c) 3 ml of CO₂/100 ml blood
(d) 2 ml of CO₂/100 ml blood

Question- During inspiration in mammals, the diaphragm becomes
(a) dome shaped
(b) raised highly
(c) flat
(d) static

Question- Combining of haemoglobin with O₂ in lungs can be promoted by
(a) decreasing CO₂ concentration in blood.
(b) decreasing O₂ concentration in blood.
(c) increasing CO₂ concentration in blood.
(d) introducing CO₂ into blood.

Question- The pharynx functions as a ___i___, whereas the larynx functions as a ___ii___.
(a) i- common passage for air and food; ii- passageway for food only.
(b) i- passageway for air only; ii- passageway for air and food.
(c) i- common passageway for air and food; iipassageway for air only.
(d) i- block to bacteria; ii- passage for air and food.

Question- The chloride shift in red blood cells is the movement of
(a) cations into the cell to balance its uptake of chloride ions.
(b) chloride ions from the blood into the glomerular filtrate for excretion.
(c) chloride ions out of the cell to balance the release of hydrogencarbonate ions.
(d) chloride ions into the cell to balance its uptake of hydrogencarbonate ions.

Question- Much developed larynx of human male is called
(a) Aristole’s lanttern
(b) Syrinx 
(c) Adam’s apple
(d) Muller’s organ

Question-Vital capacity of our lungs is
(a) total lung capcity minus residual volume.
(b) inspiratory reserve volume plus tidal volume.
(c) total lung capacity minus expiratory reserve volume.
(d) inspiratory reserve volume plus expiratory reserve volume.

Question- Maximum amount of oxygen is exchanged from the blood in the ……………
(a) capillaries-surrounding tissue cells.
(b) arteries of the body.
(c) left auricle of the heart.
(d) capillaries surrounding the alveoli.

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