Pö ÿalima 02-26-10
Cell Division
You will need your computer today
10.2 Goals
I will be able to explain what happens
in the cell cycle.
I will be able to explain and identify
the stages of mitosis.
Mitosis
10.2
Cell cycle = Life span of the cell
 G1 phase – cell grows,
makes more organelles
and proteins
G1 phase
 S phase – chromosome
replication (S = synthesis =
“to make”)
S phase
G2 phase
Chromosomes and Chromatid
Each chromosome made of two
identical chromatids.
Attached together by the
centromere
Cell cycle = Life span of the cell
 G1 phase – cell grows,
makes more organelles
and proteins
G1 phase
 S phase – chromosome
replication (S = synthesis =
“to make”)
 G2 phase – molecules
and organelles required
for cell division produced
 M phase – mitosis and
cytokinesis
 Interphase – G1, S, G2
S phase
G2 phase
CELL DIVISION
Eukaryotes (cells with a nucleus) go
through 2 stages of division
Mitosis – division of the nucleus
Cytokinesis – division of the cytoplasm
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 the
centromere
Metaphase
 Chromosomes line up
across center of the
cell (“equator” or
“metaphase plate”)
 Centriole pairs at
opposite ends of the
cell
 Centromere
connected to the
spindle fibers
Anaphase
 Sister chromatid split
apart
 Chromosomes get
pulled to opposite
poles by the shrinking
spindle fibers
Telophase
Chromosomes
decondense
Nuclear envelope
reforms around
each set of
chromosomes at
opposite ends of
the cell
2 nuclei are formed
Cytokinesis
Division of the
cytoplasm
2 new daughter
cells are formed
with the same
number of
chromosomes as
the original cell.
Video of Mitosis
 http://highered.mcgrawhill.com/sites/0072437316/student_view0/chapter11/anim
ations.html#
 http://www.youtube.com/watch?v=s1ylUTbXyWU&featur
e=related
Name the stages…
Try This Virtual Lab
 http://bio.rutgers.edu/~gb101/lab2_mitosis/section1_fram
es.html
Homework
Online Mitosis W/S
Mitosis Flipbook. Include:
Interphase, pro-, meta-, ana-, telo-, cytokinesis
Homework
Pg. 249 #1-6
Pg. 257 #13-14