Transcript Cell Division/Cell Cycle

Hey teacher, I keep
counting, but that’s not the
answer I come up with…
TEAM QUESTION 1:
What are the stages that
people go through during
their life, starting with infancy
(newborn) and ending in their
elderly years (old age)?
UNLIKE the life cycle, it begins again when
the cell divides.
Skin
Blood
Muscle
Daughter
Cells
A cell makes EXACT replicas or copies of itself.
ENTIRE organism reproduces.
FOUR cells NOT two.
 Mitosis


Happens in all body
cells
Produces 2 cells that are
identical to the parent
cell
Cell Division Overview
 Process
cells go
through in order
to make new
cells
 The cell cycle
has 3 parts
1. Interphase
2. Mitosis/Meiosis
3. Cytokinesis
Cell Animation
Interphase is where the
cell spends most of its
life.
During this stage the
cell is performing its
normal functions and is
not dividing.
It is growing and getting
prepared to divide
Interphase has 3
stages
1. G1 –Cell doubles in
size and organelles
get larger or
duplicate
2. Synthesis –DNA
replicates (makes a
copy)
3. G2 –Cell double
checks to make sure
it is ready to divide
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
Mitosis is where the
nucleus divides into
two.Happens in
body cells (skin, liver,
stomach etc.)
Creates cells with
the same number of
chromosomes as
original cell
(humans=46)
Needed for growth
and repair of cells
Has 4 stages(PMAT)
Nucleolus disappears
 Nuclear membrane
breaks down and starts
to disappear
 Chromatin (DNA
strands) shorten and
thicken into chromatids
and connect together
at the centromere to
form chromosomes
 Spindle Fiber Apparatus
(SFA) forms

 Chromosomes
move to the
center of the
cell and
attach to
spindle fibers
 Chromatids
separate and
move to
opposite side
of the cell
 The spindle
fibers pull them
apart




Animal Cells – cell
membrane pinches
in and reforms
Plant Cells – plate
forms in middle of
the cell
Nuclear membrane
reforms
Chromosomes uncoil
back to chromatin



Happens when sperm
and egg cell are
being formed.
A type of cell division
that results in ½ the
chromosomes
needed (humans =23)
Goes through 2
divisions, but only
makes one copy of
DNA (PMAT PMAT)



The cell is completely
split.
In mitosis 2 cells are
formed that are
identical (diploid =
46 chromosomes)
In meiosis 4 cells are
formed that contain
half of the DNA
(haploid = 23
chromosomes)