Question

The word anisotropic band of a skeletal muscle fibre refers to its

• A. Light band
• B. Z line
• C. Dark band
• D. Both A and B

Answer 1

The correct option is C Dark band

The word anisotropic band of a skeletal muscle fiber refers to its dark band. It is the dark-staining zone of a sarcomere. A sarcomere is a segment between two neighboring Z-lines (or Z-discs, or Z bodies). Surrounding the Z-line is the region of the I-band (for isotropic). I-band is the zone of thin filaments that is not superimposed by thick filaments. Following the I-band is the A-band (for anisotropic) which is named for their properties under a polarizing microscope. An A-band contains the entire length of a single thick filament and appears darker.

Hence the correct option is C.