Amoeboid movement and muscle contraction require which of the following?

Amoeboid movement and muscle contraction involve the dynamics of cytoskeletal components, primarily actin filaments, which play a crucial role in both processes.

In amoeboid movement, cells such as amoebas extend and retract their pseudopodia through the polymerization and depolymerization of actin. This creates the protrusions needed for the cell to move and allows it to crawl along surfaces. The ability of actin to rapidly assemble and disassemble is essential for the flexibility and adaptability required in amoeboid movement.

Similarly, in muscle contraction, actin interacts with myosin filaments in a cycle of binding and pulling that is essential for muscle fibers to shorten and generate force. The sliding filament mechanism of muscle contraction relies on the coordinated actions of actin and myosin, where actin serves as the thin filament that moves relative to the thick myosin filaments.

While myosin is also essential for muscle contraction, the context of the question asks for something that is a key player in both processes, making actin the more appropriate choice. Collagen and fibronectin are structural proteins involved in providing support and stability within tissues but do not play a direct role in the movement mechanics of amoeboid movement or muscle