Select Chapter Topics:
Q. No.
Assertion (A):
Special vascularised structures called gills are used by most of the aquatic arthropods and molluscs.
Reason (R):
Terrestrial arthropods also possess gills.
1.
Both (A) and (R) are true and (R) is the correct explanation of (A).
2.
Both (A) and (R) are true but (R) is not the correct explanation of (A).
3.
(A) is true but (R) is false.
4.
Both (A) and (R) are false.
Subtopic: Â Respiratory Organs |
 70%
Level 2: 60%+
Hints
| Assertion (A): | Alveoli are the major site of exchange of gases. |
| Reason (R): | CO2 and O2 are exchanged at alveoli by simple diffusion. |
| 1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
| 3. | (A) is true but (R) is false. |
| 4. | Both (A) and (R) are false. |
Subtopic: Â Respiratory System: Trachea & Basic Anatomy of Lung |Â Respiratory System: Exchange of Gases |
Level 3: 35%-60%
Hints
| Assertion(A) | Pneumotaxic centre can moderate the functions of the respiratory rhythm centre. |
| Reason(R) | Neural signal from pneumotaxic centre can reduce the duration of inspiration and thereby alter the respiratory centre. |
1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is not the correct explanation of (A).
3. (A) is true but (R) is false.
4. Both (A) and (R) are false.
Subtopic: Â Respiratory System: Regulation of Respiration |
 83%
Level 1: 80%+
Hints
| Assertion (A): | Hb cannot get saturated with O2 more than 70%. |
| Reason (R): | The affinity O2 to Hb increases with the rise of pCO2. |
| 1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
| 3. | (A) is True but (R) is False. |
| 4. | Both (A) and (R) are False. |
Subtopic: Â Respiratory System: Transport of Gases Part 1 |Â Respiratory System: Transport of Gases Part 2 |Â Respiratory System: Transport of Gases |
 69%
Level 2: 60%+
Hints
Given below are two statements:
| Assertion (A): | Inspiration occurs when intra-pulmonary pressure is lower than atmospheric pressure. |
| Reason (R): | Inspiration is initiated by the relaxation of diaphragm and intercostal muscles. |
| 1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
| 3. | (A) is true but (R) is false. |
| 4. | Both (A) and (R) are false. |
Subtopic: Â Respiratory System: Exchange of Gases |
 86%
Level 1: 80%+
Hints
| Assertion (A): | In the walls of bronchi and bronchioles are present stretch receptors. |
| Reason (R): | Stretch receptors are stimulated by overstretching of the lungs. |
| 1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
| 3. | (A) is true but (R) is false. |
| 4. | Both (A) and (R) are false. |
Subtopic: Â Respiratory System: Trachea & Basic Anatomy of Lung |
 50%
Level 3: 35%-60%
Hints
Given below are two statements:
| Assertion (A): | CO combines with Hb at the same point on Hb as does O2. |
| Reason (R): | CO binds with Hb about 200 times faster than O2. |
| 1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
| 3. | (A) is true but (R) is false. |
| 4. | Both (A) and (R) are false. |
Subtopic: Â Respiratory Disorders: Part 1 |Â Respiratory Disorders: Part 2 |Â Respiratory Disorders - III |
 60%
Level 2: 60%+
Hints
| Assertion (A): | Nasopharynx is a portion of pharynx present above the soft palate at the back of the nose. |
| Reason (R): | Major chamber opens into nasopharynx through the internal nares. |
| 1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
| 3. | (A) is true but (R) is false. |
| 4. | Both (A) and (R) are false. |
Subtopic: Â Respiratory System: Trachea & Basic Anatomy of Lung |
 66%
Level 2: 60%+
Hints
| Assertion (A): | The tracheae, primary, secondary and tertiary bronchi and initial bronchioles are supported by incomplete cartilaginous rings. |
| Reason (R): | The cartilaginous rings prevent these structure from collapsing. |
| 1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
| 3. | (A) is True but (R) is False. |
| 4. | Both (A) and (R) are False. |
Subtopic: Â Respiratory System: Trachea & Basic Anatomy of Lung |Â Respiratory Organs |
 83%
Level 1: 80%+
Hints
| Assertion (A): | The two lungs are covered by a double-layered pleura, with pleural fluid between them. |
| Reason (R): | Pleural fluid reduces the friction on the lung surface. |
| 1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
| 3. | (A) is true but (R) is false. |
| 4. | Both (A) and (R) are false. |
Subtopic: Â Respiratory System: Trachea & Basic Anatomy of Lung |
 89%
Level 1: 80%+
Hints
Select Chapter Topics:
© 2026 GoodEd Technologies Pvt. Ltd.