Asked in PMC Practice Test 32 (2021) 2021Moderate

What is the basic unit of muscle fibre?

Correct answer: A. myofibril

  • A. myofibril
  • B. Z-line
  • C. M-line
  • D. Fibroin

Explanation

Correct option:A(Definition) The basic unit of muscle fiber is the myofibril. Myofibrils are long cylindrical structures found within muscle fibers that are responsible for muscle contraction. They are composed of repeating units called sarcomeres, which contain the contractile proteins actin and myosin.

Last updated

About Muscles

Muscles covers skeletal, smooth and cardiac muscle, their microscopic structure and the roles of tendons, myofibrils, actin and myosin. It explains the sliding filament mechanism, sarcomere shortening, neuromuscular transmission and calcium regulation, while distinguishing voluntary skeletal movement from involuntary contraction in smooth and cardiac muscle.

Practise Support and Movement

738 free Support and Movement MCQs from Biology, each with the correct answer and an explanation. Unlimited attempts, no account needed.

Exams that ask Biology questions like this

Biology is on 6 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.

Related questions