Contractile unit of muscle is part of myofibril between

1.  Z-line and l-band

2.  Z-line and Z-line

3.  Z-line and A-band

4.  A-band and l-band 

The ion that must be present in an adequate amount for binding of cross-bridges with actin is 

1.  $C{a}^{+2}$

2.  $N{a}^{+}$

3.  $K^{+}$

4.  $M{g}^{+2}$

According to the sliding filament theory of muscle contraction, the filament that move to shorten a muscle are 

1.  Myosin

2.  Actin

3.  Collagen

4.  Creatine phosphate 

In a contracted skeletal muscle fiber

1.  M line disappears

2.  H-zone elongates

3.  l-band remains constant

4.  A-band disappears 

Sheet or broadband of fibrous connective tissue that is deep to the skin and surrounds entire muscles and other organs of the body are

1.  Epimysium

2.  Fascicule

3.  Endomysium

4.  Fascia 

The muscle is a specialised tissue which is originated from

1.  Endoderm

2.  Mesoderm

3.  Ectoderm

4.  Yolk sac 

A collagenous connective tissue layer hold the muscle bundles together.

1.  Perimysium

2.  Endomysium

3.  Epimysium

4.  Fascia 

The plasma membrane of the muscle fibre is called

1.  Sarcoplasma

2.  Sarcolemma

3.  Sarcoplasmic Reticulum

4.  Syncytial 

The dark band present on myofibril is

1. Isotropic band

2. Anisotropic band

3. Hensen's zone 

4. M-line

The structural and functional unit of myofibril which contracts to cause movement is called

1.  Sarcolemma

2.  Sarcomere

3.  Fascia

4.  Myosin