MitosisMitosis

By Joey CordBy Joey Cord

Period 4Period 4

March 26March 26thth, 2009, 2009

Definition Definition –Noun The usual method of cell division,

characterized typically by the resolving of the chromatin of the nucleus into a threadlike form, which condenses into chromosomes, each of which separates longitudinally into two parts, one part of each chromosome being retained in each of two new cells resulting from the original cell.

Definition from http://dictionary.reference.com/browse/mitosis

Chromosomes Chromosomes In the mitosis process, the nucleus and In the mitosis process, the nucleus and

the genetic information in the nucleus the genetic information in the nucleus (Chromosomes) duplicate, or make a (Chromosomes) duplicate, or make a copy of themselves. After this occurs, copy of themselves. After this occurs, the chromosomes are “pulled” apart and the chromosomes are “pulled” apart and two identical cells are made. This two identical cells are made. This Process is illustrated below.Process is illustrated below.

The NucleusThe Nucleus In biology, the nucleus is often referred In biology, the nucleus is often referred

to as “The Control Center” of the cell. to as “The Control Center” of the cell. That is because the nucleus controls the That is because the nucleus controls the cells function and reproduction. It also cells function and reproduction. It also contains the genetic material of the cell. contains the genetic material of the cell. This material is organized into multiple This material is organized into multiple long linear DNA molecules in complex long linear DNA molecules in complex with a large variety of proteins, such as with a large variety of proteins, such as histones, to form Chromosomes.histones, to form Chromosomes.

The Steps Of Mitosis

InterphaseInterphaseThe Phase in which The Phase in which the cell prepares for the cell prepares for division.division.

ProphaseProphaseAt the onset At the onset of prophase, of prophase, chromatin chromatin condenses condenses together together into a highly into a highly ordered ordered structure structure called a called a chromosomechromosome..

PrometaphasePrometaphaseThe nuclear envelope disassembles and The nuclear envelope disassembles and microtubules invade the nuclear space. microtubules invade the nuclear space. This is called open mitosis, and it occurs This is called open mitosis, and it occurs in most multicellular organismsin most multicellular organisms

MetaphaseMetaphaseThe The centromeres of centromeres of the the chromosomes chromosomes convene convene themselves on themselves on the metaphase the metaphase plate, an plate, an imaginary line imaginary line that is that is equidistant equidistant from the two from the two centrosome centrosome poles.poles.

AnaphaseAnaphaseAnaphase begins abruptly with the Anaphase begins abruptly with the regulated triggering of the regulated triggering of the metaphase-to-anaphase transition. metaphase-to-anaphase transition. At this point the Anaphase becomes At this point the Anaphase becomes activated. This terminate activity by activated. This terminate activity by cleaving and inactivating the M- and inactivating the M-phase cyclin required for the phase cyclin required for the function of M-phase function of M-phase cyclin dependent kinases (M-Cdks). It (M-Cdks). It also cleaves also cleaves securin, a protein that , a protein that inhibits the inhibits the protease known as known as separase. Separase then cleaves . Separase then cleaves cohesin, a protein responsible for , a protein responsible for holding sister chromatids togetherholding sister chromatids together

Telophase Telophase

Telophase (sometimes spelled telephase), from the ancient Greek "τελος" (end) and "φασις" (stage), is a stage in either meiosis or mitosis in a eukaryotic cell reversing the effects of prophase and prometaphase events.

Information gathered from http://en.wikipedia.org/wiki/Telophase