MCQ + Subjective question for Class 11 Biology Ch 17 Breathing and Exchange of Gases

Welcome student, today we presented the MCQ + Subjective question for Class 11 Biology Ch 17 Breathing and Exchange of Gases, this will cover the whole NCERT, and prepared you for the exams even it helps in competition exams, I recommend you to first read important points to remember of this chapter which publishes by us click here for it. Attempt all the Questions. 

Question 1. 
Cutaneous respiration is carried out by 

(A) moist skin 
(B) lungs 
(C) trachea 
(D) cuticle 

Answer

(A) Moist skin

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Question 2. 

lies in front of esophagus.
(a) Trachea
(b) Glottis
(c) Larynx
(d) Epiglottis

Answer

(A) Trachea

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 Question 3. 

Why is the mechanism of breathing different for different organisms? 

(A) to meet their needs

(B) to help them adapt to their environment

(C) to suit their mod of life

(D) all of the above 

Answer

(D) all of the above

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 Question 4. 

How do lower invertebrates like sponges exchange gases 

(A) diffusion 

(B) osmosis

(C) breathing 

(D) cuticle exchange 

Answer

(A) Diffusion

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 Question 5. 

Which organ doesn't  lies in thoracic cavity?
(a) Heart
(b) Lungs
(c) Pancreas
(d) Both 1and 2

Answer

(C) Pancreas

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 Question 6. 

What special name is given to the vascularised bags of terrestrial animals

and vascularised structures of aquatic arthropods and molluscs?

 (a) Gills and lungs respectively

 (b) Lungs and trachea respectively

 (c) Lungs and gills respectively

 (d) Gills and trachea respectively

Answer

(C) Lungs and gills respectively

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 Question 7. 

Assertion (A) : Breathing is different from respiration.

 Reason (R) : Breathing is physical and respiration is biochemical.

 (a) If both (A) and (R) are correct and (R) is the correct explanation of (A)

 (b) If both (A) and (R) are true, but (R) is not the explanation of (A)

 (c) If (A) is true but (R) is false

 (d) If both (A) and (R) are false

Answer

(a) if both (A) and (R) are correct and (R) is the correct explaination of (A(

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 Question 8. 

Assertion : The larynx is called the sound box.

 Reason : The larynx is a cartilaginous box that helps in sound production.

 (a) If both (A) and (R) are correct and (R) is the correct explanation of (A)

 (b) If both (A) and (R) are true, but (R) is not the explanation of (A)

 (c) If (A) is true but (R) is false

 (d) If both (A) and (R) are false

Answer

(A) Both are true and R is correct explaination of Assertion

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 Question 9. 

A man respire about 

(A) 40 times 

(B) 72 times 

(C) 12 - 16 times 

(D) none of these 

Answer

(C) 12 - 16 times

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Question 10. 

In which form CO2 is Carried in blood 

(A) sodium Bicarbonate 

(B) Sodium Carbonate 

(C) potassium Carbonate 

(D) potassium Bicarbonate 

Answer

(C) Potassium Carbonate

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Subjective Question

1. Name the organ in human respiratory system which produces sound.

Answer

Larynx (Sound box(

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2. How many oxygen molecules can be carried out by one haemoglobin
molecule

Answer

Four Molecules

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3. Give the name and function of a fluid filled double membranous layer which
surrounds the lungs. 

Answer

Pleura. It reduces the friction and the two pleura together and the protect the lungs.

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4. Which organ of our respiratory system acts as primary site of exchange of
gases ?

Answer

Alveoli of lungs

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5. Cigarette smoking causes emphysema. Give reason.

Answer

Cigarette smoking damages alveolar walls due to alveolar sacs remaining filled with air leading to decreased respiratory surface for exchange of gases

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6. Name the principle or process of exchange of gases.

Answer

Diffusion

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7. What is the role of oxyhaemoglobin after releasing molecular oxygen in the
tissues ?

Answer

Amino group of reduced haemoglobin combines with CO2 forming carbaminohaemoglobin to transport CO2.

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8. Name the muscles which facilitate breathing.

Answer

External and internal Intercoastal Muscles, situated between ribs

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9. How is the entry of food prevented in the respiratory tract ?

Answer

During swallowing a cartilaginous flap like structure called epiglottis covers the glottis and prevents the entry of food into respiratory tract.

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10. About 97% of O2 is transported by RBCs in the blood. How does the remaining
3% of O2 transported ?

Answer

By diffusion in plasma

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11. Draw a labelled diagram of a section of an alveolus with a pulmonary
capillary

Answer

Piece 🔥

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12. Following is the table showing partial pressure (in mm Hg) of oxygen and
carbondioxide) at different parts involved in diffusion in comparison to those
in atmosphere. Fill in the blank –a, b, c and d.

Answer

(a) - 159, (b) - 40, (c) - 45, (d) - 95

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13. Name the organs of respiration in the organisms.
 (a) Flatworms (b) Birds (c) Frog

 (d) Cockroach

Answer

Flatworms - body surface,
Birds - Lungs,
Frog - skin and lungs,
Cockroach - Trachea

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14.  What are occupational respiratory disorders ? What are their harmful effects ? What precautions should a person take to prevent such disorders ?

Answer

Occupational Respiratory Disorders are the Disorders which causes According to the person's occupation. It has serious harmful effects such as a person works instine grinding will have a risk of lungs Damage, and other person according to their occupation can have the damage of defence mechanism, we should wear protective mask to protect ourselves.

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15. How is respiration different from breathing ?

Answer

Slow oxidation of food to release of energy is called Respiration, while breathing is just a biophysical process which is the first step kf respiration.

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