Mitosis Online Lab Background: Cell division is the division of one cell into two smaller cells, each with identical DNA. Cells complete this process for various reasons: growth, increase in cell number, replacing damaged tissue, replacing worn and dead cells. Mitosis is the distinct process of dividing just the nuclear material into two identical nuclei. Both animal cells and plant cells complete this process of mitosis. However, it is to be noted that not all cells go through cell division, ex: nerve cells do not reproduce.. Purpose: In this investigation, the process of mitosis will be examined through microscopic pictures and the rate of mitotic phases can be estimated by counting the number of cells in a given view. Materials: computer with access to the internet, textbook Procedure: Part A 1. Go to this web site: http://www.biology.arizona.edu/cell_bio/cell_bio.html 2. Click on "Cell cycle and Mitosis" 3. Click on "Mitosis" 4. Read the information and answer questions #1-5 in analysis section. Part B 9. Go back to the website from step 1. 10. On LEFT side under “ACTIVITIES” --click on the "Online Onion Root-tip: phases of mitosis" ALSO ON LEFT SIDE OF SCREEN! 11. Read information and then click on "next". 12. Read ALL the information to help you in determining which cell is in which phase. 13. Before you start the data collection, make sure you make a copy of the data table for your data section. 14. Complete the lab and then answer the rest if the analysis questions. Data: (Copy-write down! the data table from the Onion-Root tip phases activity) Analysis: Answer all questions in complete sentences! 1. Which phase is not considered part of mitosis? 2. What is happening during this phase from question 1? 3. Why can prophase be distinguished from interphase under a microscope? 4. Why do the chromosomes line up in the center in metaphase? 5. What happens in telophase? 6. From the onion-root data, which phase appeared the most? least? 7. Which phase, based on your data collected, does a cell spend most of its time? 8. Which phase does a cell spend the least of its time? 9. Why was an onion-root used for this lab?