Chapter 5 The mitotic cell
->
cycle
Growth and reproduction
·
Cells reproduce by dividing and
passing on
copies of their
genes to
daughter cells .
This process
·
controlled so vital information
must be no
genetic is lost .
·
Nucleus divides before a cell divides , therefore each DC contain it's own nucleus
·
All cells in multi cellular
organisms are
genetically identical except, gametes ,
because
they all come from I cell
,
the
Zygote
·
The Zygote goes under nuclear division , mitosis
,
followed by cell division this ,
is the mitotic cell cycle
Chromosomes
·
Structure of a chromosome
essential for division
Double
·
Structure
Chromatid 1
·
of C identical parts of a chromosomes
There are two chromatids because during interphase each DNA molecule in a nucleus
makes identical of itself
(sister chromatids) an
copy
DNA
·
is the molecule of inheritance and is made up of series of
a
genes .
·
DNA molecules ,
one in each of the Sister chromatids are identical , so
genes too
·
When cells divide , one chromatid
goes into one daughter cell and one in the other , making them identical .
A precise
·
scaffolding made of protein molecules prevents the DNA from
being tangled ,
DNA is wound around the outside
Chromatin -
Combination of DNA and proteins
Most proteins react DNA
·
basic , histones ,
are
easily with
The cell
cycle
Mitosis
·
is nuclear division that produces two genetically identical daughter nuclei , with same number of chromosomes .
·
Cell Sequence division until
-
of events that takes place from
Cycle one cell .
the next
↳ :
3 phases Interphase nuclear division/mitosis division /
, ,
cell
Cytokinesis .
, Interphase
·
Cell grows to it's normal Size after division and carries out it's normal functions
S phase
·
At Some
point during interphase ,
a
Signal may be received that the cell should divide again so the DNA in the nucleus replicates so
each chromosome consists of 2 identical chromatids .
·
G phase Cells make the RNA ,
enzymes and the other proteins needed for
growth At . the end , the cell becomes committed to
dividing or not .
r
& phase cell continues to
grow and DNA that made
during Sphase is checked . Errors repaired and preparations made
-
new was are are
to
begin division .
M
·
phase (nuclear division) growth stops temporarily during mitosis
-
.
The Mitotic cell cycle
After the M phase when the nucleus is divided into two , the whole cell divides to create
two identical cells
genetically .
In
-
animal cells, cell division involves the constriction of the cytoplasm between the
two nuclei , process called Cytokinesis .
In plant cells
-
,
it involves the formation of a new cell wall between the two nuclei .
Mitosis
As the cell changes shape the
,
surface area of the cell increases
as the two new cells form , so new cell membrane is made .
Plant cells differ in 2
:
way
1) Don't contain centrosomes
2) After nuclear division a new cell wall must form between
daughter nuclei
->
cycle
Growth and reproduction
·
Cells reproduce by dividing and
passing on
copies of their
genes to
daughter cells .
This process
·
controlled so vital information
must be no
genetic is lost .
·
Nucleus divides before a cell divides , therefore each DC contain it's own nucleus
·
All cells in multi cellular
organisms are
genetically identical except, gametes ,
because
they all come from I cell
,
the
Zygote
·
The Zygote goes under nuclear division , mitosis
,
followed by cell division this ,
is the mitotic cell cycle
Chromosomes
·
Structure of a chromosome
essential for division
Double
·
Structure
Chromatid 1
·
of C identical parts of a chromosomes
There are two chromatids because during interphase each DNA molecule in a nucleus
makes identical of itself
(sister chromatids) an
copy
DNA
·
is the molecule of inheritance and is made up of series of
a
genes .
·
DNA molecules ,
one in each of the Sister chromatids are identical , so
genes too
·
When cells divide , one chromatid
goes into one daughter cell and one in the other , making them identical .
A precise
·
scaffolding made of protein molecules prevents the DNA from
being tangled ,
DNA is wound around the outside
Chromatin -
Combination of DNA and proteins
Most proteins react DNA
·
basic , histones ,
are
easily with
The cell
cycle
Mitosis
·
is nuclear division that produces two genetically identical daughter nuclei , with same number of chromosomes .
·
Cell Sequence division until
-
of events that takes place from
Cycle one cell .
the next
↳ :
3 phases Interphase nuclear division/mitosis division /
, ,
cell
Cytokinesis .
, Interphase
·
Cell grows to it's normal Size after division and carries out it's normal functions
S phase
·
At Some
point during interphase ,
a
Signal may be received that the cell should divide again so the DNA in the nucleus replicates so
each chromosome consists of 2 identical chromatids .
·
G phase Cells make the RNA ,
enzymes and the other proteins needed for
growth At . the end , the cell becomes committed to
dividing or not .
r
& phase cell continues to
grow and DNA that made
during Sphase is checked . Errors repaired and preparations made
-
new was are are
to
begin division .
M
·
phase (nuclear division) growth stops temporarily during mitosis
-
.
The Mitotic cell cycle
After the M phase when the nucleus is divided into two , the whole cell divides to create
two identical cells
genetically .
In
-
animal cells, cell division involves the constriction of the cytoplasm between the
two nuclei , process called Cytokinesis .
In plant cells
-
,
it involves the formation of a new cell wall between the two nuclei .
Mitosis
As the cell changes shape the
,
surface area of the cell increases
as the two new cells form , so new cell membrane is made .
Plant cells differ in 2
:
way
1) Don't contain centrosomes
2) After nuclear division a new cell wall must form between
daughter nuclei
