The  site  where  myosin  heads  bind  to actin  in  skeletal  muscles  are  covered by:: (A) Tropomyosin, (B) Troponin, (C) Calcium, (D) None of the above
Answer is A. In the resting state, the tropomyosin molecules lie on top of the active sites of the actin strands, so that attraction cannot occur between the actin and myosin filaments to cause contraction.