CHAPTER 10
THE CELL CYCLE
http://www.biology.arizona.edu/cell_bio/activities/cell_cycle/graphics/cell_cycle_animation.gif
CELL GROWTH
 A LIVING THING GROWS BECAUSE
IT PRODUCES MORE AND MORE
CELLS
http://student.ccbcmd.edu/courses/bio141/lecguide/unit6/genetics/DNA/DNArep/images/interphase1_pc.jpg
CELL GROWTH
 SURFACE AREA OF A CELL
DETERMINES HOW LARGE IT CAN
GROW
–Surface area is critical for passage
of food, oxygen, and water
entering and leaving the cell
*** to solve the problem of
getting too large, the CELL
DIVIDES
http://www.mesoblast.com/images/images-mesoblast_cell_division_still.jpg
RATES OF CELL GROWTH
CELLS CAN GROW
AT ASTONISHING
RATES UNDER IDEAL
CONDITIONS, BUT
REAL CONDITIONS
ARE FAR FROM
IDEAL
CONTROLS ON CELL GROWTH
Depends on function
http://biounder.kaist.ac.kr/~shy821/images/skin
2stem_630x.jpg
•Depends on food,
crowding, conditions in
surrounding area.
•If injury occurs (cells will
grow rapidly at the site)
http://www.burn-recovery.org/images/burn-classification.jpg
•Consequences of
uncontrolled cell growth
are severe.
http://www.upmccancercenters.com/images/prostate/image7_sm.gif
•Cancer cells have lost their
ability to control their growth
rate.
Breast cancer cells
http://ashoutinthestreet.files.wordpress.com/2009/06/breas
tcancercells.jpg
Definitions
CELL DIVISION -
The process whereby the cell
divides into 2 daughter cells
http://3.bp.blogspot.com/_7XmD8w1yTeY/R4Cy_XjD
NjI/AAAAAAAAABk/P7fx2NiM-zM/s320/cytokin.gif
MITOSIS –
process by which
the nucleus of a
cell is divided
into 2 nuclei;
occurs in somatic
(body) cells;
produces diploid
Diploid vs. Haploid

Diploid – a cell that contains both sets of
homologous chromosomes (two sets);
represented by the symbol 2N
– Found in somatic or body cells (ex. Skin,
digestive tract)
– Example : Humans – 2N = 46

Haploid – a cell that contains only a
single set of chromosomes (one set);
represented by the symbol N or 1N
– Found in gametes or sex cells – sperm &
egg
– Example: Humans – N = 23
CHROMOSOMES –
Structures in the
cell that contain the
genetic information
that is passed on
from one
generation of cells
to the next
http://www.stanford.edu/group/pandegroup/folding/education/GAH/chromosomes.jpg
CHROMATIN – The
material of which
chromosomes are made
http://www.all-science-fairprojects.com/science_fair_projects_encyclopedia/upload/7/79/Chromatin_c
hromosome.png
CHROMOSOMES
THE CELLS OF
EVERY
ORGANISM
CONTAIN A
SPECIFIC
NUMBER OF
CHROMOSOMES
http://2.bp.blogspot.com/_7XmD8w1yTeY/R4Cm2HjDNZI/AAAAAAAAAAU/1vRUnLLuwFg/s320/chromosome_chromatid_split.jpg
 HUMANS HAVE 23 PAIR OR 46
CHROMOSOMES
http://openlearn.open.ac.uk/file.php/2355/M150_2_014i.jpg
THE CELL CYCLE
Interphase -->
MADE UP OF 3
PARTS – preparing
to divide
http://www.sciencecentric.com/images/news/mitosis_300_364.jpg
Mitosis -->
MADE UP OF 4 PARTS the division of the nucleus
Cytokinesis --> MADE
UP OF 1 PART
division of the cytoplasm
http://www.biologyreference.com/images/biol_01_img0100.jpg
INTERPHASE
A.
GAP 1 (G1)
Cellular growth and
development takes place
B.DNA SYNTHESIS (S)
DNA is replicated
C.
GAP 2 (G2)
Organelles
Synthesis of
PHASES OF MITOSIS
PHASES OF MITOSIS
A.
PROPHASE
–Centrioles separate from each
other and move to the poles
–Nuclear Envelope breaks down and
Nucleolus disappears
–CHROMATIN COILS UP AND
BECOMES VISIBLE AS
CHROMOSOMES
–Chromosomes become attached to
the Spindle Fibers at the
centromere
 B.
METAPHASE
Chromosomes line up across the
equator (middle) of CENTRIOLES
the cell
SPINDLE
FIBERS
CHROMOSOME

C.
ANAPHASE
 CENTROMERES SPLIT
CAUSING THE CENTER
CHROMATIDS TO
SEPARATE, BECOMING
INDIVIDUAL
CHROMOSOMES
Continue to move in
2 groups near the
poles
D.
TELOPHASE
Opposite of Prophase
–Chromosomes uncoil
into a tangle of
chromatin
Nuclear
Envelope
reforms
around
chromatin
Nucleolus
becomes
CYTOKINESIS
Division of
the
cytoplasm
into the 2
daughter
SHORTCUT TO REMEMBER
THE CELL CYCLE
 I nterphase
I
 P rophase
 Passed
 M etaphase
 Math
 A naphase
 At
 T elophase
 Tom
 C ytokinesis
 Clark
Animation of Mitosis


http://www.loci.wisc.edu/outreach/biocli
ps/CDBio.html
http://www.youtube.com/watch?v=VlN7
K1-9QB0