Why is an Onion Root tip a good specimen to view mitosis?

Question

Why is an Onion Root tip a good specimen to view mitosis?

Answer 1

cause its very easy to get a really thin strip of onion without cutting or smashing the cells

Answer 2

The root tip is an embryonic tissue with rapidly dividing cells.  Since there are so many cells dividing, it is almost certain that you will be able to observe all the stages of division in a single section through the root tip.  

The chromosomes are large, easily seen with high power lens (450X) and not so numerous as to be difficult to see individual chromosomes.

A single onion will have numerous roots emerging from the bulb so lots of tips can be harvested.

Any root tip of an actively growing plant could be used.