A summarized power point on cell division - mitosis

2. * Chromosomes form when the chromatin network in the nucleus
of the cell, coil up, shortens and thickens.
* Each organism has a specific amount of chromosomes.
* All humans have 46 chromosomes.
* These chromosomes are arranged in identical pairs called
homologous chromosome pairs –
* Therefore humans have 23 homologous pairs of chromosomes.
* These chromosomes is only visible during cell division
processes.
* One chromosome consist of 2 chromatids and one centromere
that attach the chromatids together.
* Each chromatid consist of genes which in turn consist of DNA.

3. *
X and Y chromosomes:
gonosomes/sexchromosomes
Colored bands
represents
different genes

4. The cell cycle includes the following phases:
* Interphase
* Mitosis
* Cytokinesis
* Growth
The result is 2 identical cells.

5. *
*Allow an organism to
grow.
*Repairs damaged
cells/tissue.
*Replace dead
cells/tissue.
*Reproduction in some
simple organisms.

6. *
* In all somatic cells (include all body cells and
excludes the sex cells – sperm/egg cells)

7. *
* CONSIST OF A FEW PHASES:
* INTERPHASE
* PROPHASE
* METAPHASE
* ANAPHASE
* TELOPHASE

8. *
* Cell builds up enough energy for division
process.
* DNA replication occurs
* Cell look normal, like before division

9. *
* Nuclear envelope and nucleolus disappear.
* Chromatin become more tightly coiled, and
condenses into individual chromosomes.
Chromosomes arrange randomly in the cell.
* Centrioli move to opposite poles, with spindle
fibers stretching between them.

10. *
* The centrioli reached the opposite poles with
the spindle fibers in between.
* The chromosomes arrange randomly on the
equator, each single chromosome attaching to
a separate spindle fiber by means of the
centromere.

11. *
* The spindle fibers pull tight.
* The centromers attaching the chromatids of
the chromosomes split in half.
* Daughter chromosomes move to opposite
poles.

12. *
* Daughter chromosomes reach poles.
* Nuclear envelope surrounds chromosomes.
* Nucleolus reappear at each pole.
* Chromosomes become less condense forming
chromatin.
* Two identical nuclei has been formed

13. *
* Invagination of the cytoplasm and plasma membrane
occurs.
(Cleavage furrow forms in animal cells and a cytoplasmic
plate forms in plant cells)
* Continues until the cell in divided into 2 separate cells.
(Identical to one another and to the original cell)

14. * Summary of the different phases in mitosis
*

15. *
* Cancer is caused by the loss of cell cycle controls in cancer cells.
* Cancer cells usually continue to divide well beyond a single
layer, forming a clump of overlapping cells called a tumor.
* Malignant tumors invade surrounding tissues and can metastasize
exporting cancer cells to other parts of the body, where they may
form secondary tumors.
* They do not exhibit anchorage dependence or density dependent
inhibition.

16. *
Ovarian cancer
cells dividing