Virtual Mitosis Lab: Part I - Onion Root Tip

Introduction:

Mitosis is considered nuclear division, since its main stages deal strictly with the nucleus and its contents (DNA). Mitosis consists of 4 major stages: Prophase, Metaphase, Anaphase, and Telophase. Mitosis is part of a larger process called the cell cycle. When a living organism needs new cells to repair damage, grow, or just maintain its condition, cells undergo the cell cycle. In this lab you are going to determine the approximate time it takes for a cell to pass through each of the four stages of mitosis. You may use your textbook and class notes to help you identify the stages of mitosis as seen under the microscope.

Purpose:

The student will correctly identify and draw four stages of mitosis using microscope slide images of onion root tips and whitefish blastulae.

Procedure:

The slides below show longitudinal sections of allium (onion) root tip. Because growth in roots occurs at the tips, this is where cells will most actively undergo mitosis. Scroll through the slides, trying to find what you consider the best examples of the four stages of mitosis. When you are confident that you have identified each stage, perform a sketch of each stage on printer paper (NOT binder paper!) Make each drawing 4 cm square. Take your time, and remember to label each drawing with the phase that it represents.

When you are done, proceed on to the next part of the lab: Mitosis in Whitefish Blastula