Excessive formation of uric acid may result in

Which of the following is an incorrect statement about myasthenia gravis?
$(I)$ It is not an autoimmune disorder.
$(II)$ It affects the neuromuscular junction.
$(III)$ It occurs due to low $Ca^{++}$ in body fluid.
$(IV)$ Paralysis of skeletal muscle is a symptom of myasthenia gravis.

Assertion: Inflammation of a skeletal joint may immobilize the movements of the joint.
Reason: Uric acid crystals in the joint cavity and ossification of articular cartilage lead to this.

Which of the following is an autoimmune disorder?

Chronic autoimmune disorder affecting the neuromuscular junction, leading to fatigue, weakening, and paralysis of skeletal muscle, is called:

Select the correct statement regarding human locomotion.