🎴 Flashcard Mode

Human muscular system - class-VIII

Card1 / 40
Mastered0
Review0
QuestionClick to flip

Sarcomere is distance between

AnswerClick to flip back
A
Two Z-lines
💡 Explanation:
  • Each myofibril(a unit of the muscle cell) has alternate dark and light bands on it.
  • The light bands contain actin and are called I-band or Isotropic band, whereas the dark band called ‘A’ or Anisotropic band contains myosin.
  •  In the center of each ‘I’ band is an elastic fibre called ‘Z’ line which bisects it. The thin filaments are firmly attached to the ‘Z’ line.
  • The ‘A’ and ‘I’ bands are arranged alternately throughout the length of the myofibrils. 
  • The sarcomere is considered as the functional unit of contraction. The portion of the myofibril between two successive ‘Z’ lines is considered as a sarcomere. Hence sarcomere is the distance between two Z lines.
  • So, the correct answer is 'Two Z-lines'.
Change Mode