Zoology - Locomotion and Movement Question with Solution | TestHub
Given below is the diagrammatic representation of a sarcomere. Mark the option with a correct description of the structure labelled as A, B, C and D in the same.
Options:
Answer:
Solution:
Here, A=Z line, B=A band, C=I band, D= H zone. There is an elastic fibre called z line that bisects each I-band. The thin filament is firmly anchored to the z line. The central part of the thick filament that is not overlapped by the thin filament is known as the H-zone. During muscle contraction, the myosin heads or cross bridges come in close contact with the thin filaments. As a result, the thin filaments are pulled towards the middle of the sarcomere. The Z line attached to the actin filaments is also pulled leading to the shortening of the sarcomere. Hence, the length of the band remains constant as its original length and the I-band shortens and the H-zone disappears.
