Download In class Cell Cycle Notes

Cell Reproduction Part 1
“All cells come from pre-existing cells.”
Cells must divide for...
 Growth
 Repair
 Reproduction
The Star of Our Show



Prior to division, chromosomes are
duplicated.
A single stranded chromosome
becomes a double stranded
chromosome.
The two strands are IDENTICAL

The identical strands
are called sister
chromatids.

They are held
together by a
centromere.
centromere
chromatids
The Cell Cycle
The Cell Cycle
 The
life of a eukaryotic cell is
traditionally shown as a cycle.
Cell Cycle Summary
 G1
– Cell growth phase
 S – New DNA is synthesized
 G2 – Preparation for cell
division
 M & C - Cell division
Mitosis
Division
of the nucleus to
form two new nuclei with
the same number and
type of chromosomes as
the parent cell.
Cytokinesis
The
division of the
cytoplasm to form two
new cells.
Before Mitosis



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Interphase is the
period between cell
division. (G1, S & G2)
Cell growth.
Chromosomes
duplicate.
Synthesis of organelles
and materials needed
for cell division.
Now it’s Mitosis Time!
Cells spend 90% of their lives
during Interphase. So, once we
get to Mitosis – it’s GO time!
Prophase


Chromatin
condenses into
chromosomes.
The nuclear
membrane
disappears.
Metaphase

Chromosomes line
up across the
equator, or center,
of the cell.
Anaphase
 Sister
chromatids are
pulled to
opposite sides
of the cell &
away from
each other.
Telophase



New nuclear
membranes appear.
Cytokinesis begins.
Chromosomes
uncoil.
After Mitosis
 Cells
undergo Cytokinesis
–The cytoplasm of the cell is
divided in half
–The cell membrane grows to
enclose each cell
 Results in TWO genetically
IDENTICAL cells
Animal Cell Cytokinesis
 The
cell
membrane is
pinched in
half by a belt
of protein
threads
Plant Cell Cytokinesis
A
cell plate
forms in the
center of the
dividing cell
then fuses to
make a new
cell wall.
1. Name That Phase!
2. Name That Phase!
3. Name That Phase!
4. Name That Phase!
LABEL THIS!
5. What is A?
A
6. What is B?
B
Question #7
A
human cell contains 46
chromosomes.

How many chromosomes will each
of its daughter cells have
following mitosis?
Question #8
__________
is the
division of the nucleus to
form two new nuclei with
the same number and
type of chromosomes as
the parent cell.
Question #9
__________
is the
division of the
cytoplasm to form two
new cells.
Question #10

Chromosomes must ____________
prior to mitosis.
A. split in half
B. duplicate
C. dance around
D. pass the AIMS test
1. Name That Phase!
PROPHASE
2. Name That Phase!
TELOPHASE
3. Name That Phase!
METAPHASE
4. Name That Phase!
ANAPHASE
LABEL THIS!
5. What is A?
A
CENTROMERE
6. What is B?
SISTER
CHROMATIDS
B
Question #7


A human cell contains 46
chromosomes.
How many chromosomes will each of
its daughter cells have following
mitosis?
ANSWER: 46
Question #8
__________
MITOSIS
is the
division of the nucleus to
form two new nuclei with
the same number and
type of chromosomes as
the parent cell.
Question #9
CYTOKINESIS
__________
is the
division of the
cytoplasm to form two
new cells.
Question #10
Chromosomes must ____________
prior to mitosis.
A. split in half
* B. duplicate
C. dance around
D. pass the AIMS test

B