Which protein prevents myosin from binding to actin in a relaxed muscle?
Tropomyosin covers myosin-binding sites on actin filaments in relaxed muscles, preventing contraction. This follows from NCERT principle where the relation explains the outcome clearly for students in simple steps.
Ref: NCERT Biology Textbook for Class XI and XII (Zoology section), Chapter: Structural Organisation in Animals and Frog, Topic: Tissues, skeletal and organ systems.