Conditions of Use
How do cells grow? Chromosomes duplicate themselves, then both of them move to opposite cell walls. The cell elongated and the plasma membran grows inward, then the cell splits. The cell divides and creates two sister cells which have everything they need from their mother cell.
These are the phases that take place when cells repair,grow,multiply,and divide.
1.Interphase: Cells may appear inactive during this stage, but they are quite the opposite. This is the longest period of the complete cell cycle during which DNA replicates, the centrioles divide, and proteins are actively produced.
2.Prophase: During this first mitotic stage, the nucleolus fades and chromatin (replicated DNA and associated proteins) condenses into chromosomes. Each replicated chromosome comprises two chromatids, both with the same genetic information. Microtubules of the cytoskeleton, responsible for cell shape, motility and attachment to other cells during interphase, disassemble. And the building blocks of these microtubules are used to grow the mitotic spindle from the region of the centrosomes.
3.Metaphase: Tension applied by the spindle fibers aligns all chromosomes in one plane at the center of the cell.
4.Anaphase: Spindle fibers shorten, the kinetochores separate, and the chromatids (daughter chromosomes) are pulled apart and begin moving to the cell poles.
5.Telophase: The daughter chromosomes arrive at the poles and the spindle fibers that have pulled them apart disappear.
6.Cytokinesis: The spindle fibers not attached to chromosomes begin breaking down until only that portion of overlap is left. It is in this region that a contractile ring cleaves the cell into two daughter cells. Microtubules then reorganize into a new cytoskeleton for the return to interphase.
The chromosomes split apart and create two cells inside one and then the cell splits to create two.
Article posted January 30, 2012 at 12:00 PM •
comment • Reads 805
Return to Blog List
Add a Comment