Cell structure varies depending on its what?

There are so many different cells types ... just think of your body, or think of different types of bacteria. Some are bacillus shaped (like a rod), some are cocci shaped (like a ball). What makes them different? Their genes! Or you could say their genetic material.

In the case of eukaryotic cells in multicellular organisms like humans, it also comes down to which genes are actually expressed that can dictate what type of cell they are but also their shape/structure.