Mitosis NotesMitosis Notes

CELL DIVISION• 1 cell ÷ into 2 identical daughter cells

(same genetic info)• Eukaryotes (cells w/ nucleus) go through 2

stages of ÷• Mitosis – ÷ of nucleus

– Cytokinesis – ÷ of cytoplasm

Cell cycle = Life span of the cell G1 phase – cell grows,

makes more organelles & proteins

S phase – chromosome replication (S = synthesis = “to make”)

G2 phase – molecules & organelles required for cell ÷ produced

M phase – mitosis & cytokinesis

S phase

G1 phase

G2 phase

Cell cycle = Life span of the cell cont…

• G1, S and G2 make up INTERPHASE. Cell spends a majority of its life in this phase.

• M phase is CELL ÷. Relatively small portion of cell’s life.

MITOSIS• 4 phases of nuclear division

Prophase• Longest phase of mitosis• Chromosomes become

visible• Centriole pairs begin to

separate• Spindle fiber forms (made

of microtubules)• Nuclear envelope breaks

down• Spindle begins to attach

to chromosomes at centromere

Metaphase• Chromosomes line up

across center of the cell

• Centromere connected to spindle fibers

• Centriole pairs at opposite ends of cell

Anaphase• Sister chromatid split

apart• Chromosomes get

pulled to opposite poles by shrinking spindle fibers

• Chromosomes form “V” shape as they get dragged through the cytoplasm

Telophase• Chromosomes

decondence• Nuclear envelope

reforms around each set of chromosomes at opposite ends of cell

• Spindle fiber breaks apart

• 2 nuclei are formed

Cytokinesis• ÷ of cytoplasm• 2 new daughter cells

are formed w/ same number of chromosomes as original cell.

Video of Mitosis

• Mitosis Movie

• http://www.cellsalive.com/mitosis.htm

• http://www.youtube.com/watch?v=CzPGhYiGyZ8• http://www.youtube.com/watch?v=vFf2dWZZtVg

Homework• Obj. 14.1 and 14.2

(Meiosis)• Make a special table

where you write similarities and differences between Meiosis and Mitosis or a Venn Diagram

• Discuss and stamp Wednesday

• Current Event due Friday

• Friday, last day to turn in progress reports (signed)

Similarities Differences