Question

part a
which region of the sarcomere gives rise to the structure (band or line) indicated by the arrow?

• the region of the sarcomere that contains only thin filaments
• the region of the resting sarcomere that only contains thick filaments
• the point of connection for adjacent thick filaments
• the boundary between adjacent sarcomeres

Explanation:

The H - band of the sarcomere contains only thick filaments (myosin). The I - band contains only thin filaments (actin). The boundary between adjacent sarcomeres is the Z - line. The region of connection for adjacent thick filaments is the M - line. The region indicated by the arrow in the sarcomere diagram is the H - band which has only thick filaments.

Answer:

the region of the resting sarcomere that only contains thick filaments