CELLULAR REPRODUCTION
, THE CELL CYCLE AND CELLULAR REPRODUCTION
cell
cycle- ordered set of
stages that happen between the time a cell divides and the
time its alls divide
resulting daughter
when cell is
going to divide-o
grows bigger ,
number of
organelles and amount of DNA doubles
phases of the cell
two
cycle
:
↳
interphase (includes number of phases
cytokinesis)
↳ mitotic (includes mitosis and
stage
INTERPHASE
makes up most of cell
cycle
to is the time when cell performs usual function
↳ amount cells complete full
of for cell spend in interphase varies
. embryonic
time to
g
, e .
cycle in a few hours , for adult mammal cells interphase takes about 20 hours (90 % of cell cycle)
of 3 G . , S , G2
consists
stages
:
En
Stage
n - before
Gy checkpoint
G
stage replication
-
-
DNA -
will occur Otherwise , the cell
after DNA replication
stage G2
>
-
.
is committed to divide when ⑳
growth signals are present
Cyc
and nutrients are available
. -
· ccur if the DNA is
in G cell recovers from previous division ,
damaged and
F and
repaired
doubles
organelles
cannot be
in size
grows
.
,
M
accumulates materials used for DNA
checkpointbly
(also just
checkpoint. Mitosis
will not continue if
Synthesis carries out normal
daily
chromosomesarSeed
e
cell)
.
functions of
some cells (e cells) complete cell arrested,
nerve and muscle do not
cycle are
permanently
-
g
.
.
exit interphase and enter phase called Go
↳ in
Go perform normal function but do not prepare for all division cannot leave Go
they
-
without proper
signals from other cells (tightly controls completion of cell cycle
S
stage
starts when DNA replication occurs
each chromosome made up of one DNA double helix -
after replication each is made up of two
identical double helix molecule
-o each double helix =
chromatid , two identical chromatids =
Sister chromatids
↳ sister attached until separated
chromatids
stay during mitosis