NEETZoologyLocomotion and Movement
What is the purpose of the "Z" line in a myofibril?
Options
- ATo contract the sarcomere
- BTo hold the thick filaments together
- CTo separate the sarcomeres
- DTo regulate the overlap of thin filaments on thick filaments
Correct answer
C. To separate the sarcomeres
Step-by-step solution
The portion of the myofibril between two successive "Z" lines is considered as the functional unit of contraction and is called a sarcomere. The striated appearance of myofibrils is due to the distribution pattern of two important proteins - Actin and Myosin. The light bands contain actin and the dark bands contain myosin.The light bands in a myofibril contain actin and is called I-band or Isotropic bandThe actin filaments are thinner as compared to the myosin filaments In a resting state, the edges of thin filamen