Final answer:
Amoebas move by extending and retracting pseudopodia, which allows them to change shape and propel themselves forward.
Step-by-step explanation:
Amoebas move by shaping themselves, a process known as amoeboid movement. They extend part of their cell body to form structures called pseudopodia (false feet), into which the remainder of their protoplasm flows. This movement mechanism allows them not only to move through their environment but also to engulf food items. Unlike organisms that use flagella or cilia for motion, amoebas rely on the projection and retraction of their pseudopodia to achieve locomotion.