Question

Class 11 Biology MCQ Questions of Breathing and Exchange of Gases with Answers?

Answer 1

Class 11 Biology MCQ Questions of Breathing and Exchange of Gases with Answers helps you for Class 11 and NEET entrance exams. Students of Class 11 definitely take this Test for a better result in the exam. You can find numerous MCQ Questions for class 11, NEET and Board exams on Sarthaks eConnect here.

Here you will get set of 20 MCQ Questions for Class 11 Biology Breathing & Exchange of Gases to study with detailed solutions. The solved MCQ Questions with answers in quiz give you a good mix of easy questions and tough questions.

Practice MCQ Questions for class 11 Biology Chapter-Wise

1. In brain, respiratory control centre lies in

(a) pons
(b) medulla oblongata
(c) hypothalamus
(d) cerebrum

2. Deoxygenated blood from heart comes to lungs via

(a) pulmonary vein
(b) systemic vein
(c) pulmonary artery
(d) systemic artery

3. Pleura is a layer covering

(a) heart
(b) kidneys
(c) lungs
(d) brain

4.  The maximum volume of air that can be released from the lungs by forceful expiration after deepest inspiration is called the ...........

(a) Total lung capacity
(b) Vital capacity
(c) Tidal volume
(d) Ventilation rate

5. Trachea divides into bronchi at

(a) 4th thoracic vertebra
(b) 5th thoracic vertebra
(c) 6th thoracic vertebra
(d) 7th thoracic vertebra

6. The lungs are enclosed in a covering called

(a) Perichondrium
(b) Pleural membrane
(c) Pericardium
(d) Peritoneum  

7. Thoracic cavity is enlarged by contraction of

(a) Internal Intercostal muscles
(b) Diaphragm
(c) Lungs
(d) All of above

8. The pneumotaxic centre is present in

(a) Medulla
(b) Cerebrum
(c) Cerebellum
(d) Pons varolii

9. Intercostal muscles occur in:

(a) abdomen
(b) thigh
(c) ribs
(d) diaphragm

10. In human beings, oblique fissures are associated with :

(a) Right lung
(b) Left lung
(c) Both lungs
(d) None of the above

11. Hemoglobin that is bonded to carbon monoxide and therefore cannot transport oxygen, is called

(a) carboxyhemoglobin
(b) methemoglobin
(c) reduced hemoglobin
(d) carbaminohemoglobin

12. Which of the following is entirely made of cartilage?

(a) Nasal septum
(b) Larynx
(c) Glottis
(d) Trachea

13. 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

14. Pneumotaxic centre which can moderate the functions of the respiratory rhythm centre is present at:

(a) Pons region of brain
(b) Thalamus
(c) Spinal cord
(d) Right cerebral hemisphere

15. Name the chronic respiratory disorder caused mainly by cigarette smoking

(a) asthma
(b) respiratofy acidosis
(c) respiratory alkalosis
(d) emphysema

16. Respiratory organ of scorpion is

(a) Book-lungs
(b) Book-gills
(c) Buccal cavity
(d) Lungs

17. The volume of air breathed in and out during normal breathing is called

(a) Tidal volume
(b) Exploratory reserve volume
(c) Vital capacity
(d) None of these

18. When you exhale, the diaphragm

(a) relaxes and arches
(b) relaxes and flattens.
(c) contracts and arches
(d) contracts and flattens

19. The alveolar epithelium in the lung is 

(a) non-ciliated columnar 
(b) non-ciliated squamous 
(c) ciliated columnar 
(d) ciliated squamous

20. What is the vital capacity of our lungs?  

(a) Inspiratory reserve volume plus tidal volume 
(b) Total lung capacity minus expiratory reserve volume 
(c) Inspiratory reserve volume plus expiratory reserve volume 
(d) Total lung capacity minus residual volume

21. The volume of air involved in breathing movements can be estimated by using

(a) ECG
(b) Sphygmomanometer
(c) spirometer
(d) Barometer

22. Earthworms breathe through their.........

(a) Pores on its anterior end
(b) Head
(c) Skin
(d) Lungs

23. Where are the conchae located?

(a) Auricle
(b) Brachioles
(c) Nasal Chambers
(d) Ville

24. Carbon dioxide is transported from tissues to respiratory surface by only 

(a) plasma and erythrocytes 
(b) plasma 
(c) erythrocytes 
(d) erythrocytes and leucocytes 

25. Two friends are eating together on a dining table. One of them suddenly starts coughing while swallowing some food. This coughing would have been due to improper movement of 

(a) Epiglottis
(b) Diaphragm 
(c) Neck
(d) Tongue 

Answer 2

1. Answer : (b) medulla oblongata

Explanation: The respiratory center is located in the medulla oblongata and is involved in the minute-to-minute control of breathing.

2. Answer : (c) pulmonary artery

Explanation: The right ventricle pumps blood from the right atrium to the pulmonary artery. The pulmonary artery sends the deoxygenated blood to the lungs, where it picks up oxygen in exchange for carbon dioxide.

3. Answer : (c) lungs

Explanation: The pleurae are serous membranes that fold back onto themselves to form a two-layered membranous structure. There are two layers; the outer pleura (parietal pleura) is attached to the chest wall and the inner pleura (visceral pleura) covers the lungs and adjoining structures, via blood vessels, bronchi, and nerves.

4.  Answer : (b) Vital capacity

Explanation: The maximum amount of air that can be breathed out through forceful expiration after a forceful inspiration is called Vital Capacity (VC). It is sum total of Tidal Volume (TV), Inspiratory Reserve Volume (IRV), and Expiratory Reserve Volume (ERV). The value for vital capacity is about 3.4 - 4.8 liters.

5. Answer : (b) 5th thoracic vertebra

Explanation: In the mediastinum, at the level of the fifth thoracic vertebra, the trachea divides into the right and left primary bronchi. The bronchi branch into smaller and smaller passageways until they terminate in tiny air sacs called alveoli.

6. Answer : (b) Pleural membrane

Explanation: The pleural membranes are two layers of the serous membranes which enclose and protect the lung. The superficial layer is called parietal pleura and lines the wall of the thoracic cavity. The deep layer is called visceral pleura and covers the lungs themselves.

7. Answer :(b) Diaphragm

Explanation: During the process of inhalation, the lung volume expands as a result of the contraction of the diaphragm and intercostal muscles (the muscles that are connected to the rib cage), thus expanding the thoracic cavity.

8. Answer : (d) Pons varolii

Explanation: The Pneumotaxic center is a neural center present in the pons region of the brain that provides inhibitory impulses on inspiration and thus prevents overdistension of the lungs and helps to maintain alternately recurrent inspiration and expiration.

9. Answer : (c) ribs

Explanation: Intercostal muscles are muscles that present within the rib cage. Consist of three layers of muscles external, internal, and innermost layer they combine to fill the space between the ribs.

10. Answer : (c) Both lungs

Explanation:  The oblique fissure, which extends from the costal to the mediastinal surface of the lung both above and below the hilum. It divides the left lung in an upper and a lower lobe and in the right lung, separates the inferior from the middle and superior lobes, and is closely aligned with the fissure in the left lung.

11. Answer : (a) carboxyhemoglobin

Explanation: Carboxyhemoglobin, or carboxyhaemoglobin, (symbol COHb or HbCO) is a stable complex of carbon monoxide and hemoglobin (Hb) that forms in red blood cells upon contact with carbon monoxide.

12. Answer : (b) Larynx

Explanation: The larynx is a cartilaginous skeleton, some ligaments, and muscles that move and stabilize it, and a mucous membrane. The laryngeal skeleton is nine cartilages: the thyroid cartilage, cricoid cartilage, epiglottis, arytenoid cartilages, corniculate cartilages, and cuneiform cartilages.

13. Answer : (a) 20-25

Explanation: As the solubility of CO₂ is 20-25 times higher than that of O₂, the amount of CO₂ that can diffuse through the diffusion membrane per unit difference in partial pressure is much higher compared to that of O₂.

14. Answer : (a) Pons region of brain

Explanation: A centre present in the pons region of the brain called pneumotaxic centre can moderate the iimctions of the respiratory rhythm centre. Neural signal from this centre can reduce the duration of inspiration and thereby alter the respiratory rate. When the pneumotaxic centre is more active, breathing rate is more rapid.

15. Answer : (d) emphysema

Explanation: Smoking causes 82 percent of emphysema chronic bronchitis among males and 76 percent among females. The main reason behind slow breathing rate or loss of breathing is rupturing of the alveoli hence they can't hold the air anymore.

16. Answer : (a) Book-lungs

Explanation: The respiratory organ of scorpion is book lung. It consists of 4 pairs of cuticular pulmonary sacs. Books lungs are formed by invaginations of cuticle at the bases of rudimentary appendages.

17. Answer : (a) Tidal volume

Explanation: Volume of air breathed in or out during normal breathing is called as tidal volume.

18. Answer : (a) relaxes and arches

Explanation: Upon inhalation, the diaphragm contracts and flattens and the chest cavity enlarges. This contraction creates a vacuum, which pulls air into the lungs. Upon exhalation, the diaphragm relaxes and returns to its domelike shape, and air is forced out of the lungs.

19. Answer : (b) non-ciliated squamous 

Explanation: The alveoli have a very thin (0.0001 mm thick) wall composed of simple moist, nonciliated, squamous epithelium. The number of alveoli is countless and their surface area enormous. This further accelerates the gaseous exchange in the alveoli.

20. Answer : (d)

Explanation: The lungs' vital capacity can be defined as the maximum amount of air exhaled by the body after maximum inhalation. The lung capacity of the individual is 4800 mL approximately. The vital capacity is the sum of tidal volume, inspiratory reserve volume, and expiratory reserve volume.

21. Answer : (c) spirometer

Explanation: Spirometer is the device used to measure the volume of air involved in breathing movements and it also helps in clinical assessment of pulmonary functions.

22. Answer : (c) Skin

Explanation: Earthworms do not have lungs; instead, they breathe through their skin. Their skin needs to stay moist to allow the passage of dissolved oxygen into their bloodstream. 

23. Answer : (c) Nasal Chambers

Explanation: The conchae are located laterally in the nasal cavity and covered by pseudostratified columnar, ciliated respiratory epithelium with a thick, vascular and erectile glandular tissue layer.

24. Answer : (a) plasma and erythrocytes 

Explanation:  The majority of carbon dioxide is transported as part of the bicarbonate system. Carbon dioxide diffuses into red blood cells. Bicarbonate leaves the red blood cells and enters the blood plasma. In the lungs, bicarbonate is transported back into the red blood cells in exchange for chloride.

25.Answer : (a) Epiglottis

Explanation: Due to improper movement of epiglottis, one may suddenly start coughing while swallowing some food. The epiglottis is a flap that is made of elastic cartilage tissue covered with a mucous membrane, attached to the entrance of the larynx. It prevents the entry of food into the larynx, and directs it to the oesophagus.

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