Question

Sliding filament theory can be best explained as

• A. Actin and myosin filaments do not shorten but rather slide pass each other.
• B. When myofilaments slide pass each other myosin filaments shorten, while actin filaments do not shorten.
• C. When myofilaments slide pass each other actin filaments shorten, while myosin filament do not shorten.
• D. Actin and myosin filaments shorten and slide pass each other.

Answer 1

The correct option is A Actin and myosin filaments do not shorten but rather slide pass each other.

According to sliding filament theory, muscle contraction is brought about by sarcomere contraction. This is result of sliding of actin and myosin filaments past each other leading to shortening of I band and disappearance of the H zone. Options B, C and D are incorrect as the sarcomere shortens while both the filaments remain the same length. Correct answer is A.