Practice question

Amoeboid locomotion relies on dynamic remodeling of actin cytoskeleton producing cytoplasmic extensions termed pseudopodia meaning false feet. Through polymerization of G-actin at leading edge forming lamellipodia and depolymerization at rear, cytoplasm streams inside projection, adhesion complexes anchor to substratum via transmembrane proteins, propelling cell forward. Small GTPases Rac and Cdc42 regulate branching. Forms include lobopodia in Amoeba, filopodia in foraminifera, and reticulopodia in radiolarians. This crawling mechanism also mediates phagocytic capture of bacteria, distinguishing amoeboid motility from swimming via cilia or flagella requiring microtubules.