Minimal mitotic activity
In the drawings below, you can see the chromosomes in the nucleus going through the process of mitosis, or division. If you have a microscope (400X) and a properly stained slide of the onion root tip (or allium root tip), you can see the phases in different cells, frozen in time. You will be looking at strands of DNA inside the cell! PHASES OF MITOSIS First Phase is called Prophase, the DNA molecules of the chromosomes condense.  It is common to see photomicrographs of onion root cells when demonstrating how cell division takes place in plants. Onions have larger chromosomes than most plants and stain dark. The chromosomes are easily observed through a compound light microscope. The cells pictured below are located in the apical meristem of the onion root. The apical meristem is an area of a plant where cell division takes place at a rapid rate. Phases of plant cells division: 1) Interphase is considered the first and last stage of plant cell division 4.4. These two images show the view that is typical when exploring an allium root tip squash. These slides are of root tips that were cut and fixed after 2 days of growing. The first is a low power image, and the second a high power close up of a portion of the same slide.  The meristematic region of the Allium (onion) is a region of active mitosis. The section is thin (one cell thick); cells are relatively large, the chromosomes take on stain nicely, are easily seen, and are few in number (around 16). In one root tip you may see examples of all five major phases of mitosis.  Materials: microscope prepared slides of onion (allium) root tips Procedure: 1. Get one microscope for your lab group and carry it to your lab desk with two hands. Make sure that the low power objective is in position and that the diaphragm is open to the widest setting.2. Obtain a prepared slide of an onion root tip (there will be three root tips on a slide). Hold the slide up to the light to see the pointed ends of the root sections. This is the root tip where the cells were actively dividing Making the world better, one answer at a time. Root tips of allium cepa (otherwise known as the onion) are popularly used for cytological studies all over the world for the following reasons: 1) Roots are easy to grow from the base of the bulb kept over a water container. 2) Good quality, unsoiled root tips are easy to obtain. Mitosis takes place in the root tip cells. The root tip of a healthy plant is growing r … apidly and there is a requirement for many newly formed cells. 1 person found this useful. These regions of growth are good for studying the cell cycle because at any given time, you can find cells that are undergoing mitosis. In order to examine cells in the tip of an onion root, a thin slice of the root is placed onto a microscope slide and stained so the chromosomes will be visible. The cells you'll be looking at in this activity were photographed with a light microsope and then digitized so you can see them on the computer. Mitosis is the name for the kind of cell division that produces a greater number of cells = cell multiplication; after division, the daughter cells are about half the size of their parent, and they grow before division occurs again. Most of the time a cell is in interphase, the growth and preparation stage of the cycle. Mitosis, the actual process of dividing has four defined phases: Prophase, Metaphase, Anaphase, and Telophase; then the daughter cells enter interphase. 4. Minimal mitotic activity in the root tip cells of Allium ceja is reached between three and four hours subsequent to treatment with 128 r of x-rays, and between two and one-half and three hours following treatment with 512 r of x-rays. Between treatment and fixation all root tips were maintained at 32 C. 5. Vicia root tip after irradiation. As is shown in Table 11, Allium root tip cells, treated with 128 r of x-rays, ex-hibit no significant decrease in late prophase frequency until two and one-half hours after treatment. The cell cycle refers to the continuing series of divisions alternating with cell growth: interphasemitosisinterphasemitosisinterphase. An acronym for the cell cycle is ...IPMAT IPMAT IPMATI... Most of the time a cell is in interphase, the growth and preparation stage of the cycle. Mitosis, the actual process of dividing has four defined phases: Prophase, Metaphase, Anaphase, and Telophase; then the daughter cells enter interphase.
http://www.microscope-microscope.org/activities/school/mitosis.htm http://www.microscopy-uk.org.uk/mag/artnov04macro/jronionroot.html http://www.nuffieldfoundation.org/practical-biology/investigating-mitosis-allium-root-tip-squash https://answers.yahoo.com/question/index?qid=20071209234323AAdOzSL http://www.nclark.net/MitosisLab.pdf http://www.answers.com/Q/Why_are_cells_on_the_root_tip_of_allium_cepa_used_in_studying_mitosis http://www.biology.arizona.edu/cell_bio/activities/cell_cycle/cell_cycle.html http://faculty.baruch.cuny.edu/jwahlert/bio1003/mitosis.html http://www.biolbull.org/content/112/3/305.full.pdf http://faculty.baruch.cuny.edu/jwahlert/bio1003/mitosis.html
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