MICROANATOMY

Detailed explanation-1: -The correct answer: During muscle contraction, myosin cross-bridges attach to B) actin filaments. Muscle contraction is a process in which the interaction between the muscle filaments takes place. The actin and myosin filaments interact with the help of the sliding movement of actin which occurs on myosin.

Detailed explanation-2: -Cross-bridges can only form where thick and thin filaments overlap, allowing myosin to bind to actin. If more cross-bridges are formed, more myosin will pull on actin, and more tension will be produced.

Detailed explanation-3: -The cross-bridge cycle begins when a myosin head (which protrudes 90 degrees from the long axis of the thick filament) with bound ADP plus an inorganic phosphate group (Pi) attaches to a myosin-binding site on the actin filament.

Detailed explanation-4: -The contractile proteins are proteins that mediate the contraction of muscles which are actin and myosin. Actin and myosin heads create a cross-bridge, causing muscle contraction. When the thin actin and thick myosin filaments slip past each other, muscle contraction takes place.