🔬 Biology · Locomotion and Movement · NEET

The central lighter region of the A band, having only thick filaments, is the:

Answer: H zone.

A I band
B Z line
C H zone
D M line

Correct answer: C. H zone

Explanation: The H zone is the middle part of the A band where only thick filaments occur, with no thin-filament overlap.

Structure of a sarcomere showing thick myosin filaments and thin actin filaments with the Z line, M line, A band, I band and H zone labelled

A sarcomere (Z line to Z line): during contraction the I band and H zone shorten as thin filaments slide over thick, while the A band stays the same length. Image: SlothMcCarty, CC BY-SA 3.0, via Wikimedia Commons.

Concept context

Types of movement, muscle contraction, skeletal system, joints, and disorders. Important for Class 11 and NEET.

Read the full Locomotion and Movement notes →

The central lighter region of the A band, having only thick filaments, is the:

Concept context

More Locomotion and Movement questions