Download Section 10-2 Cell Division

Section 10-2: Cell Division
 Cells divide for:
o Growth of organism & keeping cell size __________________:
1) exchange of materials (oxygen, food, wastes)
2) allows DNA to control needs of cell
o ________________________: replace old cells or repair
damaged cells.
 Chromosomes: made of DNA and carry the genetic information
 Human cells have ________________________
 Duplicate before cell division which makes sure each new cell
has a copy of genetic information:
1) Duplicated pairs of chromosomes are called
________________________.
2) Chromatids are held together by a __________________.
 ________________________: cycle of growth and division by a
cell (4 phases)
 Interphase:
G1 – growth
S - DNA copies itself
G2 – cell prepares for cell division
 Cell begins division in M phase = ___________________
 ________________________: nuclear division of a cell that results in
2 cells with the same genetic information.
 Four phases: PMAT
 ________________________:
1) first phase where chromosomes can be seen
2) centrioles move to opposite sides
3) spindle forms & fibers attach to chromosomes
4) nucleolus & nucleus disappear
 ____________________________
1) chromosomes line up in the center
 ____________________________
1) chromosomes separate at centromere
2) individual chromosomes move to opposite sides of the
cell
 ____________________________
1) final phase of mitosis
2) nucleus begins to form around each set of chromosomes
3) spindle disappears
4) nucleolus reappears
 ____________________________: division of the cytoplasm
 Animals – cell pinches in and 2 cells have formed
 Plants – a __________________________ forms separating the 2
new nuclei, then cell wall forms.
Section 10-3: Regulating the Cell Cycle
 ___________________________ are special proteins that regulate
the cell cycle in eukaryotes. Examples: internal regulators, external
regulators
 _________________________: uncontrolled cell division that forms
masses of cells or tumors.
 Causes:
1) __________________________: greater risk of developing
cancer if family member has it.
2) __________________________: ultraviolet radiation (excess
sun exposure), air pollution, virus infection
3) __________________________ choices: tobacco use, diet,
lack of exercise
4) Defect in __________________________ which normally
stops cell cycle if duplication process of chromosomes is not
finished.
* _________________________ leading cause of death in U. S.
Section 10-2: Cell
Division
 Cells divide for:
o Growth of organism
& keeping cell size
small:
1) exchange of
materials (oxygen,
food, wastes)
2) allows DNA to
control needs of cell
o Maintenance: replace
old cells or repair
damaged cells.
 Chromosomes: made
of DNA and carry the
genetic information
 Human cells have 46
chromosomes
 Duplicate before cell
division which makes
sure each new cell has
a copy of genetic
information:
1) Duplicated pairs of
chromosomes are
called chromatids.
2) Chromatids are held
together by a
centromere.
 Cell Cycle: cycle of
growth and division by
a cell (4 phases)
 Interphase:
G1 – growth
S - DNA copies
itself
G2 – cell prepares
for cell division
 Cell begins division
in M phase = Mitosis
 Mitosis: nuclear
division of a cell that
results in 2 cells with the
same genetic
information.
 Four phases: PMAT
 Prophase:
1) first phase where
chromosomes can be
seen
2) centrioles move to
opposite sides
3) spindle forms &
fibers attach to
chromosomes
4) nucleolus & nucleus
disappear
 Metaphase
1) chromosomes line
up in the center
 Anaphase
1) chromosomes
separate at centromere
2) individual
chromosomes move to
opposite sides of the
cell
 Telophase
1) final phase of
mitosis
2) nucleus begins to
form around each set
of chromosomes
3) spindle disappears
4) nucleolus reappears
 Cytokinesis: division
of the cytoplasm
 Animals – cell
pinches in and 2 cells
have formed
 Plants – a cell plate
forms separating the 2
new nuclei, then cell
wall forms
Section 10-3:
Regulating the Cell
Cycle
 Cyclins are special
proteins that regulate the
cell cycle in eukaryotes.
Examples: internal
regulators, external
regulators
 Cancer: uncontrolled
cell division that forms
masses of cells or
tumors.
 Causes:
1) genetic or
hereditary: greater risk
of developing cancer if
family member has it
2) environmental:
ultraviolet radiation
(excess sun exposure),
air pollution, virus
infection
3) lifestyle choices:
tobacco use, diet, lack
of exercise
4) defect in gene p53
which normally stops
cell cycle if duplication
process of
chromosomes is not
finished.
o Second leading cause
of death in U. S.