Which one of the following statements are correct?

(i) In the resting state, a subunit of troponin mask the active binding sites for actin on the myosin filament.

(ii) Many monomeric proteins called meromyosin constitute one thick filament.

(iii) The head and short arm of Heavy Meromyosin projects outwards at regular distance and angle from each other from the surface of a polymerized myosin filament is known as cross arm.

(iv) Mechanism of muscle contraction is best explained by sliding filament theory.

(v) A receptor neuron along with the muscle fibres connected to it constitute a motor unit.

(vi) Neuromuscular junction is also called motor-end plate.

(vii) A neural signal reaching neuromuscular junction releases a neurotransmitter acetyl choline which generates an action potential in the sarcolemma.

(viii) Repeated activation of the muscle can lead to accumulation of lactic acid due to aerobic breakdown of glycogen in them causing fatigue.

(ix) Muscle contains a colourless oxygen storing pigment called myoglobin.

(x) Number of mitochondria is low in white fibres compare to red fibres and number of sarcoplasmic reticulum is high is white fibres than in red fibres.

(xi) In humans, skeletal system is made up of 206 bones. The axial skeleton is made up of 126 bones.

Choose the correct option given below: