| QUESTION | ANSWER | EXPLANATION |
| Exchange of air occurs in _______ which are also known as 'air sacs'. | Alveoli | Gaseous exchange occurs in alveoli. Due to the presence of alveoli, surface area of the lungs for exchange of gases increases to a great extent.  |
Identify bronchus in this diagram.
 | B | |
Write the correct sequence of the pathway through which air travels after entering the body.
A. Larynx, pharynx, trachea bronchioles
B. Pharynx, larynx, trachea, bronchioles
C. Pharynx, larynx, bronchioles, trachea
D. Pharynx, trachea, larynx, bronchioles | B | The blue arrows in the following diagram denote the passage of air in the respiratory tract after entering through the nostrils. |
Which process does not occur in the nasal cavity?
A. Trapping of large foreign bodies
B. Exchange of gases
C. Humidification of inhaled air
D. Warming of inhaled air | B | Gaseous exchange occurs in lungs. |
Normal rate of respiration in an adult human being is _______ times/ minute.
A. 10-12
B. 12-14
C. 16-18
D. 22-24 | C | |
Spirometer measures:
A. Capacity of lungs
B. Volume of air inhaled and exhaled
C. Residual air
D. All of these | D | Spirometer is an instrument used to measure various lung volumes and lung functions. |
Identify diaphragm in this diagram.
| E | Diaphragm is a respiratory muscle which lies underneath the lung bases. |
Complete the equation:
Glucose + Oxygen = _______ + Water + CO2 | Energy | In the tissues, glucose reacts with oxygen to produce energy which is used in various cell activities. Water and CO2 are formed as by-products. |
| What is the leaf-like structure which prevents the entry of food into respiratory passages? | Epiglottis | |
| Which part of the respiratory tract is also known as the voice box? | Larynx | Voice is produced in the larynx; therefore it is also known as the voice box. |
| Which cells of the blood carry oxygen to different parts of the body? | Red blood cells | Hemoglobin present in the red blood corpuscles (RBCs) carries oxygen to different parts of the body. |
| True or False: Trachea contains 16-20 'C'-shaped cartilaginous rings. | True | Cartilagenous rings prevent the trachea from collapsing. |
| True or False: Breathing through the mouth is considered as good as breathing through the nose. | False | Hairs and mucus present in the nasal cavity trap the foreign particles and bacteria and thus prevent them from entering the body. This function cannot be achieved when we breathe through the mouth. |
| True or False: Exhalation and inhalation of air is known as "cellular respiration". | False | Various metabolic activities of the body need oxygen for energy and produce CO2 as an end product. This exchange of gases at the cellular level is known as cellular respiration. |
| True or False: Two-layered membrane which covers the lungs is known as pericardium. | False | It is 'pleura'. Pericardium covers the heart. |
