Download 2013-Mitosis PPT

1
2
Cell Cycle…
• Does your cell cycle look something like this?
3
4
Cellular
Division
5
Identical Daughter Cells
Two
identical
daughter
cells
Parent Cell
6
Chromosomes
7
Chromosomes in Dividing Cells
Duplicated
chromosomes are
called sister
chromatids &
are held
together by the
centromere
Called Sister Chromatids
8
Boy or Girl?
The Y Chromosome Decides
Y - Chromosome
X - Chromosome
9
Cell Reproduction
10
Types of Cell Reproduction
Asexual reproduction involves a
single cell dividing to make 2 new,
identical cells, these are called
daughter cells
Mitosis & binary fission are examples of
asexual reproduction
Sexual reproduction involves two
cells (egg & sperm) joining to make a
new cell (zygote) that is NOT
identical to the original cells
Meiosis is an example
11
Cell Cycle
DNA Copied
Cells
Mature
Daughter
Cells
Cells prepare for
Division
Cell Divides into
Identical cells
12
What’s Happening in Interphase?
What the cell looks like
Animal Cell
What’s occurring
13
Mitosis
14
Mitosis
Division of the
nucleus
Only occurs in
eukaryotes
Produces somatic
cells (ALL but
sex cells)
Has four stages
Doesn’t occur in
some cells such
as brain cells
15
Four Mitotic Stages
Prophase
Metaphase
Anaphase
Telophase
16
Early Prophase
Chromatin in nucleus continues
condensing
Mitotic spindle forms from centrioles
Microtubules make up the spindle fibres
Nucleolus
Cytoplasm
Nuclear Membrane
Chromosomes
17
Late Prophase
Nuclear membrane & nucleolus are
broken down
Chromosomes continue condensing &
are clearly visible
Spindle fibers attach to the
centromere of each chromosome
Spindle begin to move to the
opposite ends of the cell, stretching
out the cell
18
Late Prophase
Chromosomes
Nucleus & Nucleolus have disintegrated
19
Review of Prophase
What the cell
looks like
Centromeres
What’s happening
20
Metaphase
Chromosomes, attached to the
centromeres and move to the center of
the cell
Chromosomes are now lined up in the
middle
21
Metaphase
Spindle
Fibers
Chromosomes
lined up in
the middle
22
Metaphase
Chromosomes
23
Review of Metaphase
What the cell looks
like
24
Anaphase
Occurs rapidly
Sister
chromatids are
pulled apart to
opposite poles
of the cell by
spindle fibers
Cell elongates
(gets wider)
25
Anaphase
Sister
Chromatids
being
separated
26
Anaphase Review
What the
cell looks
like
What’s
occurring
27
Telophase
Sister chromatids are now at
opposite poles
Spindle disassembles
Nuclear envelope forms around
each set of sister chromatids
Nucleolus reappears
CYTOKINESIS begins at the end
of this stage
Chromosomes reappear as
chromatin
28
Comparison of Anaphase & Telophase
29
Cytokinesis
Means division of the cytoplasm
Division of cell into two,
identical halves called daughter
cells
30
Mitotic Stages
31
Daughter Cells of Mitosis
Have the same number of
chromosomes as each other and as
the parent cell from which they
were formed
Identical to each other, but smaller
than parent cell
Must grow in size to become mature
cells (G1 of Interphase)
32
Identical Daughter Cells
Chromosome number the same
33
Review
of
Mitosis
34
Name the Mitotic Stages:
Interphase
Telophase
start
Prophase
Metaphase
Anaphase
35
Eukaryotic Cell Division
 Used for growth and
repair
 Produce two new cells
identical to the original
cell
 Cells are diploid (2n)
Prophase
Metaphase
Chromosomes during
Metaphase of mitosis
Anaphase Telophase Cytokinesis
36
REMEMBER…
 PMAT + Cytokinesis
C
y
P
M
A
T
o
t
a
l
p
a
p
o
h
p
h
p
a
h
a
h
s
a
s
a
e
s
e
s
r
e
e
n
e
e
t
o
k
i
n
e
s
i
s
37
Mitosis in Onion Root Tips
Do you see any stages of mitosis?
38
Test Yourself
over Mitosis
39
Name the Stages of Mitosis:
Anaphase
prophase
Metaphase
Interphase
Prophase
cytokinesis
Telophase,
Prophase
Anaphase
40
Identify the Stages
?
Prophase
?
?
Metaphase
Prophase
Anaphase
Anaphase
?
?
Telophase
?
?
Telophase
41