Transcript ch 10 Cell Cycle

Ch 10
The Cell
Cycle
Chapter 10.1
Cell Growth
Do Now 1/19:
• Do we grow because our cells are
larger or because we have more
of them? Explain your reasoning.
• Take out 10 vocab hw
I. Why should cells divide?
1. DNA overload
a. There is only one original copy of DNA in
each cell
b. If the cell gets too big, the DNA can not
serve it.
c. A small library can only serve a small
town. More people = the library needs
more books
2. Exchanging Materials
a. Food, O2, H2O into a cell, CO2 and waste
out through the cell membrane
b. If the cell is too big, not enough
nutrients will be moved in and too much
waste will build up.
c.There would not be enough surface area
for the increasing volume
3. Surface Area to Volume
Ratio
a. Volume increases more rapidly than the
surface area.
Surface area = (length x width)(number of sides)
Volume = length x width x height
Surface area/volume = ratio
Figure it out…
Exit Card
• Why is it important for cells to remain
small?
• http://www.mheducation.ca/school/applets/
sf10/unit3/surfacearea.html
• https://www.youtube.com/watch?v=wuXS
EOKNxN8
Do Now 1/19
• Explain why cells must divide when they
get too large (Give at least 2 reasons).
• Take out vocab.
That first cell had all the information and
instructions to make you as you are now.
It was all in a secret code in the middle of
the cell.
This code is called DNA. It is a very long
list of instructions that gives each cell in
your body its own shape and function.
• That first cell grew a little and then "wiggly" bits
called chromosomes could clearly be seen.
Half of the chromosomes came from the egg
cell, and half from the sperm cell and each
chromosome contained two copies of that secret
code, the plans to make you
• The first cell then divided into two separate cells
using a process called cell division and this is
how it happened...
• First the chromosomes lined up in the
center of the cell.
Then each chromosome split into two
identical halves.
Next the cell made a fold down its middle
and...
HEY PRESTO!!!
Two cells, which both had all the information
and instructions to make you...and then...
Those
cells grew a bit...
copied their chromosomes and
those
became
then
then became
then
then
then
then
became
You get the
idea…
Then:
Very soon there were
If one of your cells was really this size you'd
be as big as the Empire State Building in
America.
II. Cell Division
A. Before the cell becomes too large:
1. It copies (replicates) it’s DNA
2. Divides into 2 equal and identical
daughter cells
III. The Cell Cycle
Happens in stages:
1. Interphase: Divided into three phases
A. G1
A Cell
B. S phase
spends the
C. G2
most time
here!
2. Mitosis/Cytokinesis
Blue
InterPhase
Red
Yellow
IV. Interphase
A. Divided into 3 phases:
1. Gap 1 (G1)-cell grows in size
2. Synthesis (S)–DNA
replicated (synthesized)
3. Gap 2 (G2)–prepares for
division
Interphase
Blue
InterPhase
Red
Yellow
V. Mitosis
• Mitosis= - DNA in
the form of
chromosomes
separate into 2
identical halves.
Divided into 4 phases:
1. prophase, metaphase, anaphase,
and telophase
Blue
InterPhase
Red
Yellow
VI. Cytokinesis
A. Cytoplasm pinches in and
separates forming 2 identical
cells
B. Proteins like Cyclins control cell division!
– Mitosis is used in multi-cellular
organisms for the division of somatic
cells (body cells)
– https://www.youtube.com/watch?v=Jc
ZQkmooyPk
VII. Chromosomes
A. Made of DNA and proteins
B. Invisible except during cell
division
(chromatinchromosomes)
C. Human cells have 46
carrot cells have 18
Exit Card
Explain why it would be detrimental to an
organism if chromosomes were not
replicated prior to mitosis.
http://www.loci.wisc.edu/outreach/bioclips/CDBio.html
http://www.biology.arizona.edu/cell_bio/tutorials/ce
ll_cycle/cells3.html
http://highered.mcgrawhill.com/sites/0072437316/student_view0/chapter11/animations.html
http://www.iknow.net/CDROMs/cell_cdrom/cellmovies.shtml
http://web.grcc.edu/biosci/pictdata/mitosis/planmito.htm
http://biology.about.com/library/blmitosisanim.htm
http://www.cellsalive.com/mitosis.htm
http://www.sci.sdsu.edu/multimedia/mitosis/navigator.html