Please refer to Chapter 17 Breathing and Exchange of Gases MCQ Class 11 Biology with answers below. These multiple-choice questions have been prepared based on the latest NCERT book for Class 11 Biology. Students should refer to MCQ Questions for Class 11 Biology with Answers to score more marks in Grade 11 Biology exams. Students should read the chapter Breathing and Exchange of Gases and then attempt the following objective questions.

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

The Breathing and Exchange of Gases MCQ Class 11 Biology provided below covers all important topics given in this chapter. These MCQs will help you to properly prepare for exams.

Question. List the set of factors from the following.
Which are responsible for dissociation of oxygen from the oxyhaemoglobin?
(a) High pCO₂, low pO₂, low pH
(b) High temperature, low pO₂, less H⁺ conc.
(c) Low pO₂, High pCO₂, High pH
(d) High pO₂, low pCO₂, high temperature.

Question. Which of the following structure doesn’t have cartilaginous rings?
(a) Primary bronchi
(b) Trachea
(c) Initial bronchioles
(d) Terminal bronchioles

Question. During inspiration.
(a) Diaphragm contracts and becomes dome shaped
(b) Diaphragm contracts and becomes flat
(c) Diaphragm relaxes and becomes dome shaped
(d) Diaphragm relaxes and becomes flat

Question. On a graph paper we have plotted the oxygen haemoglobin curve of haemoglobin seen in thec enmbryonic stage. A new oxygen haemoglobin curve of haemoglobin seen in a 10-year-old child is plotted on the same graph paper. With respect to this graph which one of the following statements is correct?
(a) The new curve is on the right of the old curve.
(b) The new curve is on the left of the old curve.
(c) The new curve completely overlaps the old curve.
(d) Data is insufficient to comment on the position of graphs.

Question. Which of the following is the correct ascending order of all pulmonary volumes?
(a) TV < RV < IRV < ERV
(b) TV < ERV < RV < IRV
(c) TV < RV < ERV < IRV
(d) IRV < ERV < RV < TV

Question. The figure given below shows a small part of human lung where exchange of gas takes place. In which one of the options given below one part A, B, C, and D is correctly identified along with its function.

(a) A-Alveolar cavity – main site of exchange of respiratory gases.
(b) D- Capillary wall – mainly made up of cuboidal epithelium
(c) B- Red blood cells – transport of mainly carbaminohaemoglobin.
(d) C-Arterial capillary – passes oxygen to tissues

Question. Wheezing occurs in:
(a) Asthma
(b) Emphysema
(c) Silicosis
(d) Asbestosis

Question. The option depicting the correct partial pressure (in mm Hg) is:

Question. Erythropoiesis may be stimulated by the deficiency of :-
(a) Iron
(b) Oxygen
(c) Protein
(d) None of the above

Question. “T” wave in an ECG represents-
(a) Atrial repolarization
(b) Atrial depolarization
(c) Ventricular repolarization
(d) Ventricular depolarization

Question. Read the following statements and chooses the correct option:
A. The first heart sound (lub) is associated with the closure of both the semilunar valves.
B. The duration between the second heart sound and the following heart sound is 0.3 seconds.
C. The cardiac output is the stroke volume multiplied by the number of heart beats per minute.
(a) A, B and C are correct
(b) A, C are correct but B is incorrect
(c) A, is correct but B and C are incorrect
(d) A, B are incorrect but C is correct

Question. If due to some injury the chordae tendinae of the mitral valve of the human heart is partly non-functional, what will be the immediate effect?
(a) The flow of blood into the pulmonary artery will be reduced.
(b) The blood will tend to flow back into the right atrium.
(c) The flow of blood into the aorta will be reduced.
(d) Both 1 and 3.

Question. The lymph collected from the body finally enters:-
(a) Sub-clavian artery which is situated just below the heart.
(b) Sub-clavian artery which is situated above the heart.
(c) Sub-clavian vein which is situated just below the heart.
(d) Sub-clavian vein which is situated above the heart.

Question. Which of the following structure is having maximum auto rhythmicity in the normal human heart?
(a) Purkinje fibres 
(b) Bundle of His
(c) AV node 
(d) SA node

Question. Which of the statements are correct about joint diastole?
a. Bicuspid and tricuspid valves are open
b. Bicuspid and tricuspid valves are close
c. Semilunar valves are open
d. Semilunar valves are closed
(a) a and c 
(b) b and d
(c) a and d 
(d) b and c

Question. The volume of air expired normally after forceful inspiration
(a) TV+ IRV
(b) TV+ERV
(c) TV
(d) None of these

Question. Assertion : Most fish when out of water, die of suffocation.
Reason : Atmospheric air contains far less oxygen content than the dissolved oxygen in water.
(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion
(b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion
(c) If the assertion is true but the reason is false
(d) If both the assertion and reason are false

Question. The partial pressure of CO₂ is minimum in the
(a) atmospheric air
(b) Alveoli
(c) Deoxygenated blood
(d) Oxygenated blood

Question. Assertion : Vital capacity is higher in athletes than non-athletes.
Reason : Vital capacity is about (c).5-(d).5 litres in a normal adult person.
(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion
(b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion
(c) If the assertion is true but the reason is false
(d) If both the assertion and reason are false

Question. What percentage of oxygen molecule is transported in a dissolved state through plasma
(a) 3
(b) 20-25
(c) 70
(d) 97

Question. Assertion : Abdominal muscles is related with respiration in animals.
Reason : Relaxation of abdominal muscles draws in air.
(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion
(b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion
(c) If the assertion is true but the reason is false
(d) If both the assertion and reason are false

Question. Binding of Oxygen with Hb is primarily related to
(a) Partial pressure of O₂
(b) Partial pressure of CO₂
(c) Hydrogen ion Concentration
(d) Temperature

Question. Which of the following factors are favourable for the shifting of Oxyhaemoglobin dissociation Curve to the left side
(a) High Temperature
(b) high pH
(c) Low pH
(d) None of these

Question. The red coloured, Fe Containing pigment present in the Human Body is
(a) Haemoglobin
(b) Myoglobin
(c) Globin
(d) Both A and B

Question. On an average, a healthy human breathes ______times/minute.
(a) 70-72
(b) 20-25
(c) 12-16
(d) 120-80

Question.Hiccups can be best described as
(a) forceful sudden expiration
(b) forceful contraction of intercostal muscles during deep breathing
(c) vibration of the soft palate during breathing while sleeping
(d) jerky incomplete inspiration.

Question. Epidermis is specialized for :-
(a) respiration
(b) absorption
(c) protection
(d) All of these

Question. During inspiration which of the following events takes place
(a) Diaphragm and external intercostal muscles contracts
(b) Diaphragm and internal intercostal muscles relax
(c) Intra Pleural pressure is less than atmospheric pressure
(d) Both A and C

Question. The common passage for food and air is
(a) nasal passage
(b) nasopharynx
(c) oropharynx
(d) pharynx

Question. Which of the following is incorrect
(a) Whale-Lungs
(b) Tadepole larva-Gills
(c) Earthworm-moist skin
(d) Spider-lungs

Question. Which of the following is true
(a) Right lungs is greater than left lungs
(b) structural and functional unit of lungs is alveoli
(c) lungs are non muscular
(d) All of the above

Question. Which of the following comprise the lungs
(a) tracheae along with network of bronchi, bronchioles and alveoli
(b) network of bronchi, bronchioles and alveoli
(c) alveoli only
(d) Both A and B

Question. Which of the following constitute the exchanging part of the respiratory system
(a) external nostrils to trachea
(b) external nostrils to primary bronchioles
(c) Respiratory bronchioles to alveoli
(d) external nostrils to terminal bronchioles

Question. Choose the wrong statement
(a) COb is the harmful molecule and released during catabolic reactions
(b) respiration will always require Ob
(c) Breathing is a part of respiration
(d) All of the above(c) Respiratory bronchiole o alveoli

Question. Which of the following is true for expiration except
(a) thoracic chamber volume reduces
(b) Diaphragm contracts
(c) pulmonary volume decreases
(d) All of these

Question. Which one of the following statements is incorrect ?
(a) The residual air in lungs slightly decreases the efficiency of respiration in mammals
(b) The presence of non-respiratory air sacs, increases the efficiency of respiration in birds
(c) In insects, circulating body fluids serve to distribute oxygen to tissues
(d) The principle of countercurrent flow facilitates efficient respiration in gills of fishes

Question. During winter a person died during sleep, the room was closed and a container with burnt charcoal was found in the room. What may be the possible reason of his death?
(a) non-availability of oxygen
(b) Hb has more affinity to combine with carbon monoxide
(c) Hb has more affinity to combine with nitrogen
(d) combined effect of (a) and (c)

Question. Which of the following factors will increase the breathing rate
(a) Acidity
(b) decrease in pH
(c) Blood pressure
(d) All of the above

Question. Respiration is controlled by
(a) medulla oblongata
(b) cerebellum
(c) hypothalamus
(d) cerebrum

Question. Book lungs are respiratory organs of
(a) Mammals
(b) Mollusca
(c) Earthworm
(d) Arachnida

Question. 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
(a) atmospheric O₂ level is less and hence more RBCs are needed to absorb the required amount of O₂ to survive
(b) there is more UV radiation which enhances RBC production
(c) people eat more nutritive food, therefore more RBCs are formed
(d) people get pollution-free air to breathe and more oxygen is available

Question. In human beings, oblique fissures are associated with :
(a) Right lung
(b) Left lung
(c) Both lungs
(d) None of the above

Question. Trachea divides into two right and left primary bronchi at the level of:
(a) Seventh cervical vertebra
(b) Third thoracic vertebra
(c) Fifth thoracic vertebra
(d) Seventh thoracic vertebra

Question. The solubility of carbon dioxide is about _____ times higher than that of oxygen across the respiratory membrane.
(a) 20-25
(b) 25-50
(c) 125-150
(d) 200-250

Question. A center that moderates the functions of the respiratory rhythm center is located in:
(a) Dorsal medulla oblongata
(b) Ventral medulla oblongata
(c) Pons Varolii
(d) Pre central gyrus of the cerebrum

Question. During normal respiration, the ventral respiratory group located in the medulla oblongata:
(a) Establishes the basic respiratory rhythm
(b) Controls the switch off point of inspiration
(c) Remains inactive
(d) Excites chemosensitive zone neurons

Question. Fibrous connective tissue builds up in the lungs causing them not to inflate properly, and actually deflating them is called:
(a) chronic bronchitis
(b) emphysema
(c) pulmonary fibrosis
(d) asthma

Question. Lungs are made up of air-filled sacs, the alveoli. They do not collapse even after forceful expiration, because of
(a) Residual Volume (RV)
(b) Inspiratory Reserve Volume (IRV)
(c) Tidal Volume (TV)
(d) Expiratory Reserve Volume (ERV)

Question. Name the chronic respiratory disorder caused mainly by cigarette smoking
(a) asthma
(b) respiratofy acidosis
(c) respiratory alkalosis
(d) emphysema

Question. Which one of the following is the correct statement for respiration in humans?
(a) Cigarette smoking may not lead to inflammation of bronchi
(b) Neural signals from pneumotoxic centre in pons region of brain can increase the duration of inspiration
(c) Workers in grinding and stone breaking industries may suffer, from lung fibrosis
(d) About 90% of carbon dioxide (CO₂) is carried by haemoglobin as carbamino haemoglobin

Question. Which two of the following changes (1-4) usually tend to occur in the plain dwellers when they move to high altitudes (3,500 m or more)?
(1) Increase in red blood cell size
(2) Increase in red blood cell production
(3) Increased breathing rate
(4) Increase in thrombocyte count Changes occurring are
(a) (2) and (3)
(b) (3) and (4)
(c) (1) and (4)
(d) (1) and (2)

Question. Frogs respire through
(a) Skin
(b) lungs
(c) buccal cavity
(d) All of these

Question. The two organisms which breath only through their moist skin are
(a) Frog and earthworm
(b) Fish and frog
(c) Leech and earthworm
(d) Fish and earthworm

Question. The exchange of gases in the alveoli of the lungs takes place by:
(a) simple diffusion
(b) osmosis
(c) active transport
(d) passive transport

Question. The process of migration of chloride ions from plasma to RBC and of carbonate ions from RBC to plasma is:
(a) chloride shift
(b) ionic shift
(c) atomic shift
(d) Na+ pump

Question. Azygous lobe is part of
(a) Lung
(b) Kidney
(c) Larynx
(d) Palate

Question. The function of pneumotaxic centre is
(a) regulate inspiration
(b) regulate rhythm
(c) increase heart rate
(d) all of the above

Question. Deoxygenated blood from heart comes to lungs via
(a) pulmonary vein
(b) systemic vein
(c) pulmonary artery
(d) systemic artery

Question. RBCs, plasma and biocarbonate are the medium for transport of carbondioxide. Maximum amount of carbon dioxide is carried by
(a) RBCs
(b) Plasma
(c) Bicarbonates
(d) All RBCs and bicarbonate carried 70 per cent of carbondixide.

Question. Which of the following statement is true?
(a) Every 100 mL of deoxygenated blood delivers approximately 4 mL of carbondioxide to the alveoli.
(b) Every 100 mL of oxygenated blood delivers approximately 4 mL of oxygen to the tissues.
(c) Every 100 mL of oxygenated blood delivers approximately 4 mL of carbondioxide to the alveoli.
(d) Every 100 mL of deoxygenated blood delivers approximately 10 mL of carbondioxide to the alveoli.

Question. Which one of the following is NOT correct?
(a) The nasal cavity warms and humidifies the air before it enters the lungs
(b) The right lung is composed of three lobes, but the left lung has only two lobes.
(c) Lung volumes and vital capacity measure lung function.
(d) The visceral pleura is in direct contact with the chest wall.

Question. The carbon dioxide is transported via blood to lungs as:
(a) dissolved in blood plasma
(b) in the form of carbonic acid only
(c) in combination with haemoglobin only
(d) carbaminohaemoglobin and as carbonic acid

Question. Which one of the following mammalian cells is not capable of metabolising glucose to carbon dioxide aerobically?
(a) Unstriated muscle cells
(b) White blood cells
(c) Liver cells
(d) Red blood cells

Question. In alveoli of the lungs, the air at the site of gas exchange, is separated from the blood by
(a) alveolar epithelium only
(b) alveolar epithelium and capillary endothelium
(c) alveolar epithelium, capillary endothelium and tunica adventitia
(d) alveolar epithelium, capillary endothelium, a thin layer of tunica media and tunica adventitia

We hope you liked the above Breathing and Exchange of Gases MCQ Class 11 Biology. In case you have any questions please put them in the comments box below and our teachers will provide you a response.