Breathing and Exchange of Gases | MCQs | FACT/DEFINITION TYPE QUESTIONS | NEET(Que 16-31 of 100)

 FACT/DEFINITION TYPE QUESTIONS

16. 

Which of the following has no specialized respiratory structures ?

 (a) Crab 

(b) Earthworm 

(c) Salmon 

(d) Ant 

... Answer is B)
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17.

Lungs are present in 

(a) mediastinum (b) pleural cavity (c) pericardial cavity (d) thoracic cavity 

... Answer is D)
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18.

Membrane separating air in pulmonary alveoli from blood capillaries is 

(a) alveolar epithelium 

(b) cardiac epithelium

 (c) endothelium of blood capillaries 

(d) both (a) and (c)

... Answer is D)
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19.

The amount of air remaining in the air passages and alveoli at the end of quiet respiration is called 

(a) tidal volume (b) inspirating reserve volume

(c) inspiratory capacity (d) functional residual capacity

... Answer is D)
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20.

In anaerobic respiration 

(a) O2 is taken in. (b) CO2 is taken in.

 (c) O2 is given out. (d) CO2 is given out. 

... Answer is D)
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21.

Every 100 ml of oxygenated blood delivers following amount of O2 to the tissues under normal physiological contition.

 (a) 5 ml (b) 25 ml (c) 50 ml (d) More than 50 m

... Answer is A)
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22.

What percentage of oxygen is carried by haemoglobin ? 

(a) 90 (b) 98 (c) 23 (d) 73

... Answer is B)
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23.

Partial pressure of oxygen in inspired and expired air is ……. and ……. mm of Hg.

 (a) 100, 46 (b) 158, 40 (c) 158, 90 (d) 100, 95

... Answer is B)
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24.

p50 value denotes

 (a) percentage of oxygen (b) partial pressure of O2 (c) percentage of haemoglobin (d) percentage of oxyhaemoglobin

... Answer is B)
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25.

In mammals, carbon dioxide is transported from tissues to respiratory surface by 

(a) plasma (b) R.B.C. (c) W.B.C. (d) both (a) and (b) 

... Answer is D)
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26.

__(i)__ in CO2 in your blood, which causes __(ii)__ in pH, would cause your breathing to speed up. 

(a) (i) An increase, (ii) a rise 

(b) (i) An increase, (ii) a drop 

(c) (i) A decrease, (ii) a rise 

(d) (i) A decrease, (ii) a drop

... Answer is B)
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27.

Carbonic anhydrase is found in high concentration in

 (a) leucocytes (b) blood plasma (c) erythrocytes (d) lymphocytes

... Answer is C)
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28.

Which of the following is the carbonic anhydrase ?

(a)Fe

(b)Zn

(c)co

(d) Mg

... Answer is B)
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29. 

From NCERT

The formation of Carbonic acid from Carbon dioxide and water has catalyzed the enzyme

1. Carbonic anhydrase

2. Carbonic anhydride

3. Carbonic hydrase

4. Both A and C

... Answer is 1)
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30. 

At tissue sites, partial pressure of CO2­ is high due to _______ process.

1. Anabolic

2. catabolic

3. Both A and B

4. Oxidative

... Answer is 2)
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31. 

Carbonic anhydrase is present in

1. R.B.C

2. Plasma

3. Both A and B

4. Tissues

... Answer is 3)
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Section showing-View Explanation with NCERT Reference below all the questions. 

16- (b) Earthworms do not have a special respiratory organ. Exchange of gases takes place through their skin. In them.

• Which is the respiratory organ of ant?

spiracles
Ants have an interesting respiratory system consisting of spiracles (tiny openings located on the outside of the exoskeleton that allow the transport of oxygen into and carbon dioxide out of ) and trachea (the respiratory ducts throughout the body)

• gills

Crabs, like many sea-dwelling creatures, have gills that they use to extract oxygen from the water in order to breathe.

• Trout and salmon, like all fish, have evolved a sophisticated breathing system to deal with life in a liquid environment. They breathe through specialized structures, their gills. The gills are found on each side of the fish's head and are arranged on four-gill arches. Each gill is made up of very fine filaments

17-(d) Lungs are conical in shape that take up most of the chest and thoracic cavity.The pleural cavity is the space, when it occurs, between the parietal and the visceral pleura.

• Is the pleural cavity in the thoracic cavity?

The pleural cavity consists of a double-layered membrane lining the inside of the thoracic cavity (parietal pleura) and the outside of the lung surface (visceral pleura)

18- (d) Alveolar epithelium and endothelium of blood capillaries are two membranes which separate air in pulmonary alveoli from blood capillaries.
Alveoli are the primary sites of exchange of gases. Exchange of gases also occur between blood and tissues. Oxygen and carbon dioxide are exchanged in these sites by simple diffusion mainly based on pressure/concentration gradient. Solubility of the gases as well as the thickness of the membranes involved in diffusion are also important factors that can affect the rate of diffusion. The diffusion membrane is made up of three major layers namely, the thin squamous epithelium of alveoli, the endothelium of alveolar capillaries and the basement substance in between them. 

19- (d) Functional residual capacity (FRC) is the volume of air remaining in the lungs after a normal expiration (ERV + RV). It is about 2300 ml.

20- (d) Anaerobic respiration uses electron acceptors other than oxygen. Although oxygen is not used as the final electron acceptor, the process still uses a respiratory electron transport chain. It is a respiration without oxygen and produces energy, carbon dioxide, lactic acid or alcohol

21- (a) Every 100 ml of oxygenated blood can deliver around 5 ml of O2 to the tissues under normal physiological conditions.

DOUBT-NCERT say every 100ml of blood can carry 5ml of oxygen (chapter 17 page no 274) …but the oxygen carring capacity of Hb is 1.34ml/gm therefore 100ml of blood (containing 15gm of Jb appx) can carry 20.1ml of oxygen.🤔is there any mistake from NCERT?

• 1 gm Haemoglobin carry 1.34 ml of Oxygen.
• 100 ml blood contain 15 gm (12–16 gm) Haemoglobin.
• 100 ml Blood carries 20 ml of Oxygen(1.34×15)
• But under normal physiological processes, 100 ml Blood delivers 25% (5ml) of Oxygen
• 1 molecule of Haemoglobin can carry maximum 4 Oxygen molecules.
• 
  
• 

• 20 ml O2 then it is 100% saturated.

  15 ml O2 then it is 75% saturated

  5 ml O2 then it is 25% saturated.

22-(b) About 98% of O2 is transported by RBC. O2 binds with haemoglobin (red coloured iron containing pigment present in the RBCs) to form oxyhaemoglobin. This process is known as oxygenation.

23-(b) Partial pressure of oxygen in inspired and expired air is 158 and 40 mm of Hg.

24- (b) p50 value is the oxygen tension at half saturation (50%) of blood. It is calculated from the measured oxygen tension and oxygen saturation by extrapolation along the oxygen dissociation curve to 50% saturation.

25-(d) CO2 is transported both by plasma and haemoglobin of blood

26. (b) An increase (i) in CO2 in blood, which causes a drop (ii) in pH, would cause your breathing to speed up

27. (c) Carbonic anhydrase is found in high concentration in erythrocytes (RBCs). Carbonic anhydrase is a zinc enzyme that speeds up the formation of carbonic acid.

28-(B)

Zn

• Active site
• Acid-Base balance
• present in - RBC
• convert- CO2 into Carbonic and Bicarbonate Ion

Fe

• present in- haemoglobin
• carry oxygen
• 1 g blood hai 15 g haemoglobin.
• 1 g haemoglobin carry 1.34ml oxygen.
• Blood carry 25% of saturation value of oxygen in normal function i.e = 5ml of total 20ml capacity.

Cu

• Synthasis of haemoglobin

Mg

• Maintain cell wall stability.