10.2 - Mitosis - Onion Cells

The image below contains plants cells located in an Onion Root tip magnified 400X. Since the root tip contains actively growing and dividing cells, it is an excellent place to observe the various stages of Mitosis.

The cells have been stained with two different types of stain. A yellow stain highlights the cell wall and a dark blue stain highlights the DNA. As you observe the cells, you should notice that the nucleus is visible in many cells, but not in all. Some of the cells are in the process of Mitosis, so the nucleus has dissolved and the DNA has condensed to form stringy, thread-like chromosomes. Read each question below and determine the number of cells at each stage of Mitosis.

	First name Last name