Transcript Mitosis Notes - Fulton County Schools

Cell Reproduction
and
Mitosis
Cell Reproduction
Remember that the Cell Theory states
that cells come from preexisting cells.
Cell Division is the process by which
new cells are produced from one cell.
Organisms grow by making more cells,
not by increasing the size of its cells!
The Cell Cycle
The cell cycle is the sequence of
growth and division of a cell.
There are two basic stages in the life
cycle of a cell:


Interphase (I), during which the cell
grows
Mitosis (M), during which the cell
reproduces.
The Cell Cycle
G1

Makes lipids, proteins,
carbohydrates
S

DNA replication
G2

Makes more proteins
and preps for mitosis
Mitosis

Cell divides
Chromosomes vs Chromatin
Chromatin

Loose uncoiled
strands of DNA
Chromosomes

Chromatin winds
around proteins to
form chromosomes
Mitosis
PMAT
4 Phases




P
Prophase
Metaphase
Anaphase
Telophase
A
M
T
Prophase
DNA condenses into
chromosomes
Nuclear membrane
and nucleolus
dissolve
Centrioles and
spindle fibers appear
Metaphase
Centrioles migrate to
poles
Spindle fibers expand
& attach to
chromosomes
Chromosomes align
along equator

Meet in the middle
Anaphase
Centromere connecting
chromatids splits
Sister chromatids
separate
Chromatids migrate to
the poles
Cell membrane begins
to crease
Telophase
Spindle fibers dissolve
Two nuclear
membranes & nucleoli
form
Cell membrane
continues to crease

Cytokinesis is the
pinching of the
membrane to form two
separate cells
Cytokinesis
Cytoplasm splits, resulting in two new
daughter cells
In plant cells, vesicles containing cell wall
material line up across the middle of the
cell and then fuse together to form the
cell plate

The cell plate separates the cell into the two
daughter cells and forms the cell wall
Control of the Cell Cycle
Cell growth and division depend on
environmental and protein signals

ENZYMES!!!
Checkpoints at certain phases

Replication is checked at G1, G2, and Mitosis
Cancer


Uncontrolled cell growth
Usually a result of damaged DNA