Transcript Document

By :
Monica L. Ruiz-Baker
Old Dominion University
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Background on the Cell Cycle and Mitosis
 The Cell Cycle has 4 stages.
C
 Myth: The cell is inactive during Interphase.
 Prior to Mitosis, the cell’s nuclear DNA replicates.
 Mitosis is the division of nuclear DNA in somatic
(non-sex) cells.
Mitosis
 During Mitosis, the cell divides its chromosomes and
separates into two identical daughter cells each
containing identical nuclei.
 Cytokenesis is the final Mitotic step whereby the
nuclei, cell membranes, cytoplasm, and organelles
divide into identical daughter cells.
T
Title Page
The Cell Cycle
Interphase Stages
Chromosomes
Mitosis
Prophase
Metaphase
Anaphase
Telophase
DNA Cell
Content
Protein Cell
Content
Questions
Images Courtesy
Of
I
The Cell Cycle
P
M
A
T
Chromosomes
Mitosis
DNA
Content
Protein
Content
Interphase Stages
C
P
 G1 : Active growth and Metabolism
Mitosis
 S : DNA synthesis and metabolism
Chromosomes
 G2: Synthesis of molecules in preparation
for cell division
Chromosomes
Mitosis
B
C
I
P
M
A
T
Chromosomes
DNA
Protein
I
Mitosis
M
Prophase
Chromosomes
 Early Prophase: Chromosomes
condense and organize
 Nuclear membrane and nucleoli
disappear
 Late Prophase: Centrioles form
 Spindle apparatus assembled and
attached to centromeres of
duplicated chromosomes
Metaphase
 Spindles use microtubules to line
up the duplicated chromosomes
along equator of cell
Mitosis
P
A
Anaphase
 Centromere of each duplicated
chromosome is separated
 Paired chromatids are pulled
apart
Mitosis
M
T
Telophase
Mitosis
B
A
 Chromosomes uncoil
 Nucleoli reappear
 Cytokenesis occurs
 Plasma membrane of the cell
pinches down along the
equator creating two separate
cells
 Two genetically identical
daughter cells are produced
C
Mitosis
DNA Content of Cells During the Cell Cycle
DNA Content of Cells During the Cell Cycle
0.70
DNA (picogram/cell)
0.60
0.50
0.40
0.30
0.20
0.10
0.00
0
2
4
6
8
10
12
14
16
Time (hrs.)
18
20
22
24
26
28
C
Mitosis
Protein Content of Cells During the Cell Cycle
Protein Content of Cells During the Cell Cycle
14.0
Protein (picogram/cell)
12.0
10.0
8.0
6.0
4.0
2.0
0.0
0
2
4
6
8
10
12
14
Time (hrs.)
16
18
20
22
24
26
28
Questions
DNA
Protein
 How long did it take the above cell to complete a single
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cycle of the cell cycle?
1
In what phase were the cells in the first 8 hours? How do
you know? 2
At approximately what time did division of the cytoplasm
occur?
3
During what interval did G1 occur? How do you know? 4
What phases in the cell cycle occurred between the 8th and
5
12th hours of the experiment?
Explain the differences in the two graphs between the 14th
and 20th hours of the experiment.
6
Q
Protein graph provides the answer!
Q
DNA graph provides the answer!
Q
Both graphs provide the answer!
Q
DNA graph provides the answer!
Q
Look at both graphs!
Q
No change in DNA content of cells. Protein content increases as
cells rebuild cellular organelles after cell division.
Both graphs reveal the answers!
Images Courtesy Of:
 Classroom Clip Art
 Fotosearch
 Developmental Biology Online
 E-Bio Lab
 Human Chromosomes
 Chromatid
Graph Data and Questions Courtesy of:
E-Bio Lab