🔬 Biology · Locomotion and Movement · NEET

During muscle contraction, the band whose length stays unchanged is the:

Answer: A band.

A I band
B A band
C H zone
D Whole sarcomere

Correct answer: B. A band

Explanation: As filaments slide, the I band and H zone shorten while the A band (length of the thick filaments) stays constant.

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.

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During muscle contraction, the band whose length stays unchanged is the:

Concept context

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