What are the differences between flagella and cilia in terms of their structure and function?

Flagella and cilia are both hair-like structures found in cells, but they have distinct differences in terms of structure and function. Flagella are longer and fewer in number, while cilia are shorter and more numerous. Flagella typically move in a whip-like motion to propel the cell, while cilia have a back-and-forth motion to move substances along the cell surface. Both structures are made up of microtubules, but the arrangement and length of these microtubules differ between flagella and cilia.