Can you delete the "Last 12 Months" and "Last Import" folders on your iPhone?

All I want on my Photos on my iPhone are just the Camera Roll and personal folders I created. I don't want Photo Library, Last Import, Last 12 Months, etc.

I've looked on both settings on the iPhone and the iPhoto on my computer.

I have an iPhone 4s by the way.

Just a pet peeve of mine haha. Any help would be much appreciated.