MITOSIS LAB (Onion Root Tip, and Whitefish Embryo)


Purpose:  To examine the phases of Mitosis and Interphase in Onion Root Tip and Whitefish Embryo


Observations:   Draw Diagrams of each phase


Diagrams:  Label each phase as follows:  all slides should be on high power.


Interphase:  label – nucleus, cell membrane, and cell wall (where appropriate)

Prophase:  label –chromosomes, nuclear membrane if visible, cell membrane and/or cell wall (where appropriate)

Metaphase: label –chromosomes, cell membrane and/or cell wall (where appropriate)

Anaphase: label – chromosomes, cell membrane and/or cell wall (where appropriate)

Telophase: label –nucleus reappearing, cell membrane pinching or cell plate.





  1. Is the area where you find most cells dividing the area nearest the tip of the root tip, or the area furthest away  from the root tip?


  1. Why would there be more cells dividing in this area?


  1. What is the shape and size of the cells in the area undergoing mitosis as compared with the cells in other areas of the root tip? ( try using low power or medium power and moving the slide around so that you can see the entire tip)


  1. What role do spindle fibers play in a dividing cell?


  1. Describe where the cell plate forms in a dividing cell.


  1. Name two differences between plant and animal mitosis.


Conclusion: The stages of mitosis have been observed.  Which stage of mitosis is the most commonly occurring one in your root tip?  Why would this be so?