The document summarizes key aspects of cell division and the cell cycle from Campbell and Reece, 2010. It describes how chromosomes condense and coil during cell division. It outlines the main phases of the cell cycle including interphase and mitosis. It also discusses the phases of mitosis in detail and how it results in two identical daughter cells. Finally, it briefly mentions how cancer cells lose cell cycle controls and continue dividing uncontrollably.

1. Campbell and Reece, 2010. Chapter 12 p. 228-243

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.


4. The cell cycle includes the following phases:
 Interphase (include G1- , S- [DNA synthesis] and G2 phase)
 Mitosis
 Cytokinesis
 Growth

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)

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

17. 
Campbell, N.A., Reece, J.B., Urry, L.A., Cain, M.L.,
Wasserman, S.A., Minorsky, P.V., Jackson, R.B. 2010. Biology
Eighth Edition. Pearson International. 12:228-243,242-243.