mitosis

Mitosis is the way cells multiply. This is the way all cells came to be around us. They all started by spontanius generation.

Spontanius generationn is the theory all living thing come from non-living things. It is predicted all living things came from green moss which is said to be the first living thing. Cells came to be around through mitosis through five stages of mitosis. Interphase is not a phase for cells it is a phase of growth and development. Nothing happens to the cell in this part of time.(4. biology.clc.uc)

In the first phase prophase is this phase the chromosomes now become visible. The chromosomes are greatley thickened and shortened but can still be contained in within the nucleur envelope. Spindle fibers start to form, and centrioles begin to move to opposite ends of the cell. It's mass is no longer a sphereically shaped zone in the cell. Prophase can last for several hours.(1. life.umd.edu)

In the next phase metaphase the centriolmes have reached opposite ends of the cell and the spindle fibers are completley formed.The chromosomes aline in the middle of the cell forming a metaphase plate. The spindle fibers attach to the center of the chromosomes. They make a microtuble attachment to the chromosomes. Several parts of the chromotad arms unwind from each other. Metaphase usually takes about 33 minutes.(3. biology. arizona)

In the next phase, anaphase, begins with the initial splitting of the chromatids at there centromeres. The chromosomes are stating unwind and the spindle fibers start to pull the chromosomes to opposite parts of the cell. Which is moving away from the metaphase plate. They move 1.5 micrometers. Microtubules and components in or near the kinetochore. After anaphase before the cells split they make a cell membrane, but if it is a plant cell it makes a membrane and a cell wall.(5. purchon)

After anaphase, the cell starts to pull into two parts. The cytoplasm starts to pinch in the middle of the cell. After the chromosomes are at the other end of the cell they start to dissapear, and a new membrain forms around the now forming sister nuclous. In plant cells this is when a cell plate forms in the middle of a cell. The two nucleus are completley formed and the cells are seperated completley. And now two new sister cells have formed and will start this process again.(2. accessexcelllence)

Refrences

1. An Introduction to mitosis 2008. 9 Feb 2009. . 2. Mitosis 2008. 4 Feb. 2009. . 3. Mitosis 2004. 6 Feb. 2009. . 4. Mitosis 2004. 5 Feb. 2009. . 5. Mitosis 2006. 10 Feb. 2009. .