CELL DIVISION BY MITOSIS

By: THEMBA MASILELA

Contributors

1. Phakathi

2. Choong,

3. guest0a84f2f.

Have your body in the pass six months? Tall/Weight

changed

Are you

taller?growing

Did your

grow?

hair

Clip your toenails?

Broken a bone recently?

Wound – how does your body

itself?

repair

Do you wonder why?

MitosisDefinition:

To create two identical daughter cells that are genetically identical to the parent cells

Continues

Mitosis conserves

chromosomenumber by allocating replicated chromosomes equally to each of the daughter nuclei.

Chromosome

Continues Mitosis is a process of cell division

Goal = production of 2 daughter cells.

The daughter cells are identical to one another and to the original parent cell.

Continues

Mitosis produced the somatic cells that now make up your body and is also the means by which your body continues to generate new cells to replace dead and damaged ones.

Acronym for MITOSIS

IPMATInterphase

Prophase

Metaphase

Anaphase

Telophase

Phases

Interphase Prophase Promatophase Metaphase Anaphase Telophase

Interphase

A nuclear envelope bounds the nucleus.

Chromosomes that were duplicated during S phase cannot be seen individually because they have not yet condensed.

The cell cycle

Continues Two centrosomes have formed by

replication of a single centrosome.

Continues

In animal cells, each centrosome

features two centrioles.

continues

Two Centrosomes have formed by replication of a

single centrosome.

In animal cells, each centrosome features two centrioles

Continues

The nucleus contains one or more nucleoli.

Prophase

The chromatin fibers

become more tightly coiled. The nucleoli disappear.

ContinuesEach duplicated chromosome appears

as two identical sister chromatids joined together at their centromeres and along their arms by cohesion's

Continues The mitotic spindle begins to form.

The spindle is composed of the microtubules and centrosomes that extend from them. Shorter microtubules that extend from the centrosomes are called asters.

ContinuesThe centrosomes move away from each other, pushed away by the lengthening microtubules between them.

Prometaphase

The nuclear envelope

fragments. The microtubules extending from each centrosome can now invade the nuclear area.

Continues

The chromosomes have become even more

condensed. Each of the two chromatids of each chromosome now has a protein structure located at

the centromere called a kinetochore

Continues

Some of the microtubules attach to the

kinetochores, becoming “kinetochore microtubules” that push and pull the chromosomes back and forth.

Continues

Non-kinetochore microtubules interact

with those from the opposite pole of the spindle.

Metaphase

Metaphase is the

longest stage of mitosis, and lasts about 20 minutes. The centrosomes are now at opposite poles of the cell.

ContinuesThe chromosomes line up on the metaphase plate, an imaginary plane that is equal distance between the spindle’s two poles. The chromosome’s centromeres lie on the metaphase plate

ContinuesThe kinetochores of the sister chromatids are attached to kinetochore microtubules reaching from opposite poles

Anaphase

Anaphase is the shortest stage of mitosis, and lasts only a few minutes. When the cohesion proteins are cleaved, anaphase begins. This allows the two sister chromatids of each pair to part.

Continues

The two daughter chromosomes begin moving toward opposite ends of

the cell as the kinetochore microtubules begin to shorten. The chromosomes move centromere first because the microtubules are attached to the centromeres. They travel at about 1 micrometer per minute.

Continues

The cell elongates as the non-kinetochore

microtubules lengthen. By the end of anaphase, the two ends of the cell have complete and equal collections of chromosomes.

Continues

Telophase

Nucleoli reappear.

The chromosomes become less condensed. Mitosis is complete.

Continues

Two daughter nuclei form in the cell.

Nuclear envelopes are formed from the fragments of the parent cell’s nuclear envelope and other portions of the endomembrane system.

Cytokinesis

The division of the cytoplasm is

usually almost complete by late telophase, so the two daughter cells appear shortly after the end of mitosis.

Continues

In animal cells, cytokinesis involves

the formation of a cleavage furrow, which pinches the cell in two

Mitosis in general

Somatic cells

(all body cells except gamete cells)

Reference list Phakathi, N. 2013. Life science grade 10: mitosis

cell division. http://www.slideshare.net/fundos/life-science-grade-10. Accessed 06 March 2014.

Choong, R. 2010. PowerPoint mitosis 1. http://www.slideshare.net/rchoong/powerpoint-mitosis-1. Accessed 06 March 2014.

guest0a84f2f. 2009. cell division by mitosis. http://www.slideshare.net/guest0a84f2f/cell-division-by-mitosis. Accessed 06 March 2014.