The energy for muscle contraction is most directly obtained from:

(1) Phosphocreatine                          

(2) ATP

(3) Anaerobic respiration                   

(4) Aerobic respiration

Repeated activation of the muscles can lead to

1. Accumulation of pyruvate due to anaerobic breakdown of glycogen

2. Accumulation of lactic acid due to anaerobic breakdown of glycogen

3. Fatigue

4. Both 2 and 3

The anaerobic contraction of skeletal muscle causes deposition or accumulation of

1.  Gluconic acid

2.  Lactic acid

3.  Pyruvic acid

4.  Hydrochloric acid 

Muscle fatigue occurs due to the accumulation of

1.  $C{O}_2$

2.  Myosin ATPase

3.  Lactic acid

4.  Creatine phosphate 

Globular head of myosin molecule act as

1.  ATPase

2.  CTPase

3.  TTPase

4.  GTPase