| Assertion (A): | The cardiac impulse which originates from SA node in human heart cannot spread directly from atria to ventricles. |
| Reason (R): | In human heart there is no continuity between cardiac muscle fibres of atria and those of ventricles except AV bundles. |
| 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. |
| Column-I | Column-II |
| 1. A patient who is B Rh- | i. A Rh- or O Rh- blood |
| 2. A patient who is A Rh- | ii. B Rh+ or O Rh+ blood |
| 3. A patient who is AB Rh- | iii. O Rh- , A Rh-, B Rh-, AB Rh- |
| 4. A patient who is O Rh- | iv. AB Rh+ blood |
| 1. | Bursting | 2. | Shrinkage |
| 3. | Bulging | 4. | Intact round cells |
| 1. | Pacemaker cells located in the atria fire before the pacemaker cells in the ventricles. |
| 2. | It takes time for epinephrine to diffuse from the atria to the ventricles to trigger contraction |
| 3. | The electrical signal generated in the right atrium is delayed at the AV node before passing to the ventricles. |
| 4. | The Na+ channels responsible for initiating ventricular contraction are inactivated and need to return to activated configuration to the electrically stimulated. |
| Animal | Altitude | Corpuscles (%) |
| Animal 1 | Sea level | 34 |
| Animal 2 | Sea level | 33 |
| Animal 1 | 4700 m | 50 |
| Animal 2 | 4700 m | 34 |
| 1. | Animal 1 is poorly adapted at high altitude as compared to animal 2 |
| 2. | Animal 2 is poorly adapted at high altitude as compared to animal 1 |
| 3. | Affinity of Hb for oxygen in animal 1 is higher at lower altitude |
| 4. | Hb of animal 2 shows higher affinity for oxygen as compared to animal 1 |
| 1. | The use of a heart to create pressure gradients necessary for blood flow |
| 2. | The ability to direct the flow of blood to certain tissues |
| 3. | The ability of respiratory pigment to transport O2 |
| 4. | The ability to return blood to the heart |
| 1. | A = Total area, B = Velocity, C = Blood pressure |
| 2. | A = Blood pressure, B = Velocity, C = Total area |
| 3. | A = Velocity, B = Total area, C = Blood pressure |
| 4. | A = Total area, B = Blood pressure, C = Velocity |
| 1. | Stops when the nerve supply to the heart is cut |
| 2. | Originates at AV-node |
| 3. | Decreases when stretch receptors in the vena cava are stimulated |
| 4. | Slows down when the activity in the vagus nerve increases |
| 1. | Right atrium of mother |
| 2. | Right atrium of foetus |
| 3. | Left ventricle of mother |
| 4. | Left ventricle of foetus |