NEETZoologyLocomotion and Movement
Identify A, B, C and D and then find out the correct statement:
Options
- AA = Z-line: thin fibrous line present between I-band. (Incorrect - the Z-line is located within the I-band)
- BB = M-line: elastic fibrous line present between A-band. (Incorrect - the M-line is not elastic and is located
- CC = Sarcomere: structural unit of relaxation. (Incorrect - the sarcomere is the structural unit of contraction
- DD = H-zone: part of thick filament not overlapped by thin filament.
Correct answer
D. D = H-zone: part of thick filament not overlapped by thin filament.
Step-by-step solution
- D correctly points to the central region of the A-band, which is the H-zone. - The H -zone is defined as the area where there are only thick (myosin) filaments and no overlapping thin (actin) filaments. All other options are incorrect for the reasons provided previously: - (1) The Z-line is within the I-band, not between them. - (2) The M -line is not an elastic line and is located within the A -band. - (3) The sarcomere is the unit of contraction, not relaxation.