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Class 11 Breathing and Exchange of Gases worksheet
CBSE Biology. Mechanism of breathing, lung volumes, gas exchange and transport, disorders. Every sheet has 20 questions in three sections and an answer key, and the numbers change every time.
Sample questions
Real questions from this chapter, as the app sets them. Tap Answer to see the answer and working.
Section A · multiple choice
- 1.
The primary site of exchange of gases in the lungs is the:
- trachea
- larynx
- bronchi
- alveoli
Answer
(d) alveoli
- 2.
A person has tidal volume 450 mL, inspiratory reserve volume 3,000 mL, expiratory reserve volume 1,100 mL and residual volume 1,200 mL. Their vital capacity is:
- 4,550 mL
- 3,450 mL
- 1,550 mL
- 2,300 mL
Answer
(a) 4,550 mL
vital capacity = ERV + TV + IRV
- 3.
A person breathes 12 times a minute with a tidal volume of 450 mL. The volume of air breathed in each minute is:
- 10,800 mL
- 462 mL
- 4,500 mL
- 5,400 mL
Answer
(d) 5,400 mL
450 × 12
Section B · short answer
- 4.
What is the difference between breathing and respiration?
Answer
Breathing is the exchange of air between the atmosphere and the lungs (inspiration and expiration). Respiration also includes the exchange of gases at the alveoli and tissues and the use of oxygen in cells to release energy.
- 5.
A person has tidal volume 450 mL, inspiratory reserve volume 2,800 mL, expiratory reserve volume 1,100 mL and residual volume 1,200 mL. Find their vital capacity and total lung capacity.
Answer
vital capacity = ERV + TV + IRV = 4,350 mL; total lung capacity = VC + RV = 5,550 mL
Section C · long answer
- 6.
Describe the mechanism of breathing.
Answer
Inspiration: the diaphragm contracts and the external intercostal muscles lift the ribs and sternum, increasing the volume of the thoracic cavity in both directions; the lungs expand, the pressure inside falls below atmospheric and air enters. Expiration: the diaphragm and intercostal muscles relax, the volume decreases, the pressure in the lungs rises above atmospheric and air leaves. Abdominal muscles help in forced breathing.
Fresh sheets for your child
In the app, every Breathing and Exchange of Gases sheet is new: the app remembers the questions your child has already had and leaves them out. Print the sheet as a PDF, or use notebook mode and write the answers in a notebook.
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