Transcript Mitosis- A Story of Cell Division

Mitosis- A Story of Cell
Division
http://www.cellsalive.
com/mitosis.htm
Remember the characteristics
of living things? Hmmm??
• 1) Made up of cells
• 2) Grow and Develop
• 3) Respond to their
Environment
• 4) Obtain and use Energy
• 5) Reproduce
• 6) DNA
• 7) Evolve over time
• 8) Maintain homeostasis
Cell Division occurs in ALL
living organisms!
•But why???
•Because in order for anything to
grow- cells must divide to make
more…
•Skin cells, Red Blood Cells, Plants
cells, Wounds healing...
The Cell Cycle
•Life presents many cycles…
•Cells are in either in an
active dividing stage or are
resting (not actively
dividing)
https://www.youtube.com/w
atch?v=Wy3N5NCZBHQ
The Parts of the Cell
involved in Mitosis
•Cell membrane
•Nucleus
•Nucleolus
•Nuclear membrane
•Chromosomes
•Centrioles
•Spindle Fibers
Chromosomes
•Chromosomes- strands of
DNA (genetic material)
containing protein.
A- chromosome
B- centromere
C- sister chromatid
•Organisms have different numbers.
Humans have 46. Fruit flies have 8 !
Interphase (G1 phase)
•Inter = between
•Interphase- Nucleolus is generally
seen (dark purple circle).
Chromosomes cannot actively be
seen- but chromosomes (DNA)
and centrioles are dividing.
4 Active Phases of Mitosis (M
phase)
•1) Prophase(like before)
Before the other stages…
•Chromosomes visible,
Centrioles begin to move to
ends of the cell, Spindle fibers
begin to form.
Metaphase
•Meta= middle
•Chromosomes meet in
the middle, and line up
along the center of the
cell.
Anaphase
•Chromosomes have
replicated (doubled)
and now will split apart
to either sides of the
cell (sister chromatids)
•Ana = (arms out)
Telophase
•Centrioles, and Spindle fibers
start to disappear.
Chromosomes are at
opposite sides of cell. New
nuclear membrane forms.
Looks like two cells !
Cytokinesis
• Dividing of the
cytoplasm
Results of Mitosis
•1) Mitosis is the division of
the nucleus
•2) Mitosis results in the
same number of
chromosomes that were in
the original cell