The Cell Cycle (Mitosis)
BY: DIANA CAMPO, YESENIA GARAY, JAIME GOMEZ, JORGE LUIS RODRIGUEZ.
THE CELL CYCLE (MITOSIS)
INTRODUCTION
The cycle that gives origin to new cells is known as mitosis that is defined as the nuclear division plus cytokinesis, and produces two identical daughter cells.This it is developed in seven stages that are:
4 Interphase
4 Prophase
4 Prometaphase
4 Metaphase
4 Anaphase
4 Telophase
4 Cytokinesis
In each one of those which happen processes that differ the one of the other one.Interphase is often included in discussions of mitosis, but interphase is technically not part of mitosis, but rather encompasses stages G1, S, and G2 of the cell cycle.
THE CELL CYCLE
Interphase: stage of growth of the cell where it gets ready for the division. G1 and G2 (gap 1 and gap 2) are characterized by protein and RNA synthesis, but no DNA synthesis. S (synthesis) is the period of DNA synthesis.
The cell is engaged in metabolic activity and performing its preparation for mitosis. The chromosomes are not observed with clarity in the nucleus.
Prophase: in this stage, the chromosomes condense in the center. The nucleus disappears. Centrioles moves to the opposed poles of the cell. We can say that it begins the true mitosis.
Prometaphase: the nuclear membrane is dissolved. Proteins attach to the centromeres creating the kinetochores. Microtubules attach at the kinetochores and the chromosomes begin moving.
Metaphase: during this stage the chromosomes are positioned in the equatorial planeof the cell. This organization helps to ensure that in the next phase, when the chromosomes are separated.
Anaphase: The paired chromosomes separate at the kinetochores and move to opposite sides of the cell. It is a process of equal allotment of the hereditary material (DNA) characteristic of the cells.
Telophase: the new nucleus is organized: the cromatic is reconstituted, adopting helical form the chromosomes, the nucleus appear, and the nuclear cover is built. The chromosomes disperse and are no longer visible under the light microscope.
Cytokinesis: it is the division of the cytoplasm, the cell it is divided in two almost same parts. In animal cells, cytokinesis results when a fiber ring composed of a protein called actin around the center of the cell contracts pinching the cell into two daughter cells, each with one nucleus. In plant cells, the rigid wall requires that a cell plate be synthesized between the two daughter cells.
Questions about Cells Cycle
1. Which are the stages in those that it is carried out the cellular division?
2. Which is it stage but it releases during the cellular cycle?
3. How many cells are obtained by mitosis?
4. That do they have the cells daughters in common?
RESOURCES
Look at the web sites given here to find information that will help you answer questions about cell research, and to gather information to use as you write your summary.
4 www.biology.arizona.edu/Cell_bio/tutorials/cell_cycle/cells3.html – 9k -
4 en.wikipedia.org/wiki/Cell_cycle – 61k -
4 www.cellsalive.com/cell_cycle.htm – 13k -
4 www.ucm.es/info/genetica/grupod/mitosis/mitosis.htm – 28k -