| 1. | a motor neuron and all of the skeletal muscle fibers innervated by the neuron's axon terminals. |
| 2. | all motor neurons and all of the skeletal muscle fibers innervated by them in a muscle. |
| 3. | a motor neuron and one skeletal muscle fiber innervated by the neuron. |
| 4. | a motor neuron and a sensory neuron. |
With respect to the red muscle fibers [Type I], the white muscle fibers [Type II] are richer in:
| 1. | Blood capillaries | 2. | Myoglobin |
| 3. | Sarcoplasmic reticulum | 4. | Mitochondria |
All the following regarding red muscle fibers are true except:
| 1. | They are adapted for slow and sustained activity |
| 2. | They have a high content of myoglobin |
| 3. | They are rich in mitochondria |
| 4. | They depend on anaerobic process for energy |
| Assertion (A): | Red muscle fibres are adapted to sudden outburst of muscular activity. |
| Reason (R): | Red muscle fibres are extremely rich in sarcoplasmic reticulum. |
| 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. | (A) is False and (R) is False. |
| Statement I: | Repeated activation of the muscles can lead to fatigue. |
| Statement II: | Repeated activation of the muscles can lead to the accumulation of lactic acid due to anaerobic breakdown of glycogen in them. |
| 1. | Statement I is correct; Statement II is correct |
| 2. | Statement I is correct; Statement II is incorrect |
| 3. | Statement I is incorrect; Statement II is correct |
| 4. | Statement I is incorrect; Statement II is incorrect |