Download mitosis cell cycle

the Cell Cycle
http://protist.i.hosei.ac.jp/pdb/Images/Sarcodina/Heliozoa/Actinosphaerium/cell_division_1.jpg
Cell Division
• Cell division is the process where a cell
divides to form 2 identical daughter cells
• It occurs as part of the cell cycle
• Cell division is done for the purposes of:
reproduction, growth and repair
http://www.healthfiend.com/wp-content/uploads/2011/04/Re-epithelialization-through-cell-division.jpg
Cell Division in Multicellular
and Unicellular Organisms
• In unicellular organisms, cell division results
in many new member that are identical to
one another through a process called
binary fission
• In multicellular organisms, cell division helps
in the organisms’ development and the
repair and renewal of cells
Cell Division of DNA
• The process of making new cells continues
everyday to replace dead and damaged cells
• This occurs in somatic cells (body cells or
non-sex cells) as oppose to gametes (sex
cells)
• The process of cell division in somatic cells
requires duplicating and separating the
DNA, this is called mitosis
The Genome
• The genome is the all of the cell’s genetic
information packaged into DNA
• Chromosomes are organized packages
of DNA (humans have 46 chromosomes)
• DNA are the molecules that contain the
genetic codes and instructions of our
bodies
http://www.accessexcellence.org/RC/VL/GG/images/http://www.genome.gov/Glossary/resources/chromosome_lg_adv.jpg
Chromosomes
• A duplicated chromosome is made of 2
sister chromatids (identical copies of the
chromosome’s DNA)
• The region where the strands connect is
called the centromere
• During synthesis in the cell cycle , the
chromosomes are duplicated, to allow for
identical genetic information for the new
cells
http://home.comcast.net/~clupold96/images/notes/chromosomes/chromosome_labeled.gif
http://www.uic.edu/classes/bios/bios100/lecturesf04am/realchromo.jpg
The Cell Cycle
• Interphase - includes 3 subphases
• G phase - “First Gap” - growth
• S phase - “Synthesis” - chromosome
1
duplication
•G
phase - “Second Gap” - completes
preparation for cell division
2
• M phase - mitosis and cytokinesis (splitting of
cytoplasm)
http://files5.pdesas.org/123010069062166246171026063048176250062207099255/Download.ashx?hash=2.2
Interphase
• Interphase - the cell duplicates organelles
and chromosomes and prepares cell for
division
• This process takes up 90% of the cell cycle
Subphases
• First Gap - G : Cellular contents are
1
duplicated (not the chromosomes)
• Synthesis: chromosomes are duplicated
• Second Gap - G : The cell “double checks”
2
the duplicated chromosomes for error,
makes repairs as needed
•G
0
- cell cycle stops
Mitosis
• The mitotic phase alternates with the much
longer interphase
• chromosomes line up in the middle of
the nucleus
• they are pulled apart at the centromere
• this separates them into 2 identical
chromatids
• 2 nuclei form around the
chromosomes and the cell splits in half
http://geneticssuite.net/files/Mitosis.jpg