Final answer:
Flagella in bacteria rotate and spin to propel the bacteria forward, whereas eukaryotic flagella are composed of microtubules and use dynein motor proteins to bend and facilitate movement.
Step-by-step explanation:
Bacteria move using flagella, which are tail-like structures that propel them forward. The motion of the flagella in bacteria causes them to rotate and spin, which propels them in a specific direction. The flagella of bacteria are made up of flagellin, a protein that is absent from eukaryotic cells. In contrast, eukaryotic flagella are structurally different, composed of microtubules that use dynein motor proteins to bend and enable movement.