Answer: actin.
- A actin
- B keratin
- C collagen
- D albumin
Correct answer: A. actin
Explanation: Thick myosin and thin actin filaments slide past each other during contraction.
A sarcomere (Z line to Z line): during contraction the I band and H zone shorten as thin filaments slide over thick, while the A band stays the same length. Image: SlothMcCarty, CC BY-SA 3.0, via Wikimedia Commons.
Concept context
Types of movement, muscle contraction, skeletal system, joints, and disorders. Important for Class 11 and NEET.