| Assertion (A): | Myosin is not a part of thin filament. | 
| Reason (R): | Meromyosin polymerises to form myosin. | 
| 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 | 
| Assertion (A): | The mechanism of muscle contraction can be explained by sliding-filament theory. | 
| Reason (R): | Muscular contraction occurs by the sliding of thick filaments over the thin filaments. | 
| 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 |