CBSE Class 11 Biology Breathing And Exchange Of Gases Worksheet Set A

BREATHING & EXCHANGE OF GASES

Q1. Explain two phases of aerobic respiration?

Q2. How does exchange of gases takes place in the following organisms:-
(a) Poriferans, coelenterates & flatworms. (b) Earthworms. (c) Arthropods
(d) Fishes, Tadpoles of frog (e) Reptiles, birds & mammals

Q3. Describe with help of labeled diagram human respiratory system.

Q4. List the steps involved in pulmonary respiration.

Q5. How is inspiration & expiration accomplished in human beings?

Q6. Define the following terms:-
(i) Tidal volume (ii) IRV (iii) ERV (iv) Residual volume

Q7. Name the apparatus by which volume of air involved in breathing can be measured.

Q8. Explain the pulmonary capacities:- IC, FRC, EC, VC & Total lung capacity.

Q9 (a) Name the factors that affect the rate of diffusion of gases in the lungs.
(b) Mention the components of the diffusion membrane of human respiratory system.

Q10 (a) What percentage of O2 is transported by RBC’s in the blood? What happens to the remaining?
(b) In what form in O₂ carried in the blood? What happens to this, form when blood reaches the tissues?
(c) Name the factors that affect the binding of O₂ to haemoglobin to form oxyhaemoglobin in the tissue.

Q11 (a) What are three forms in which CO₂ is transported in blood? Explain.
(b) How does CO₂ gets released into the alveoli.

Q12 (a) Where is respiratory rhythm centre located?
(b) How does pneumotoxic centre alter the respiratory rate? Where is it located in human?

Q13 (a) What is asthma? Explain. (b) What is emphysema? What are its major causes?
(c) What are occupational disorders? Give two examples of such disorders.

Important Questions for NCERT Class 11 Biology Breathing and Exchange of Gases

Ques. Although much CO2 is carried in blood, yet blood does not become acidic, because
(a) CO₂ is continuously diffused through the tissues and is not allowed to accumulate
(b) in CO₂ transport, blood buffers play an important role
(c) CO₂ is absorbed by the leucocytes
(d) CO₂ combines with water to form H₂CO₃ which is neutralised by NaCO₃.

Answer: B

Ques. The carbon dioxide is transported via blood to lungs mostly
(a) in combination with haemoglobin only
(b) dissolved in blood plasma
(c) in the form of bicarbonate ions
(d) as carbamino-haemoglobin and as carbonic acid. 

Answer: C

Ques. Carbon dioxide is transported from tissues to respiratory surface by only
(a) plasma and erythrocytes
(b) plasma
(c) erythrocytes
(d) erythrocytes and leucocytes.

Answer: A

Ques. When you hold your breath, which of the following gas changes in blood would first lead to the urge to breathe?
(a) Falling CO₂ concentration
(b) Rising CO₂ and falling O₂ concentration
(c) Falling O₂ concentration
(d) Rising CO₂ concentration 

Answer: D

Ques. The respiratory centres, which control inspiration and expiration, are located in
(a) diencephalon (b) medulla oblongata
(c) cerebellum (d) spinal cord.

Answer: B

Ques. The respiratory centre which regulates respiration is located in
(a) cerebellum (b) medulla oblongata
(c) cerebral peduncle (d) the vagus nerve.

Answer: B

Ques. Due to increasing air-borne allergens and pollutants, many people in urban areas are suffering from respiratory disorder that cause wheezing due to
(a) reduction in the secretion of surfactant by pneumocytes
(b) benign growth on mucous lining of nasal cavity
(c) inflammation of bronchi and bronchioles
(d) proliferation of fibrous tissues and damage of
 

Answer: C

40. Which of the following options correctly represents the lung conditions in asthma and emphysema, respectively?
(a) Inflammation of bronchioles; Decreased respiratory surface
(b) Increased number of bronchioles; Increased respiratory surface
(c) Increased respiratory surface; Inflammation of bronchioles
(d) Decreased respiratory surface; Inflammation of

Answer: A

Ques. Which of the following is an occupational respiratory disorder?
(a) Anthracis (b) Silicosis
(c) Botulism (d) Emphysema

Answer: B

Ques. Name the chronic respiratory disorder caused mainly by cigarette smoking.
(a) Respiratory acidosis (b) Respiratory alkalosis
(c) Emphysema (d) Asthma

Answer: C

Ques. Asthma may be attributed to
(a) inflammation of the trachea
(b) accumulation of fluid in the lungs
(c) bacterial infection of the lungs
(d) allergic reaction of the mast cells in the lungs.

Answer: D

Ques. Name the pulmonary disease in which alveolar surface area involved in gas exchange is drastically reduced due to damage in the alveolar walls.
(a) Pneumonia (b) Asthma
(c) Pleurisy (d) Emphysema 

Answer: D

Ques. Which one of the following is the correct statement for respiration in humans?
(a) Cigarette smoking may 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.

Answer: C

Ques. Blood aCnalysis 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 unusually high content of
(a) carbon disulphide (b) chloroform
(c) carbon dioxide (d) carbon monoxide.

Answer: D

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

Answer: D