Question
Biology Question on locomotion and movement
Which statement is correct for muscle contraction
Length of H-zone become decrease
Length of A-band remains constant
Length of I-band become increase
Length of two Z-line become increase
Length of A-band remains constant
Solution
The myofibril is composed of both thick and thin bands. The thick band is referred to as the dark band, while the thin band is known as the I band. Within the A-band, there exists a paler zone called the H-band located at its center. The I band is divided in its center by dense and narrow lines. The A-band is primarily formed by thick myosin filaments. As muscle contractions occur, actin filaments slide over the myosin filaments, leading to the shortening of a sarcomere. Therefore, the accurate statement is that the 'Length of the A-band remains constant.
So, the correct option is (B): Length of A-band remains constant