 Questions
of the Day!
 List the portions of Interphase and what
happens in each part.
 List the steps of mitosis and the dance moves
associated with the steps
 Sometimes a cell’s DNA changes during the
process of the cell cycle. What do you think
happens if the changed cell is allowed to
reproduce?
 What measures would need to be in place to
ensure that a changed cell is not allowed to
divide?
CH. 9.3 – CELL CYCLE REGULATION
 Normal
cell cycle is
regulated by cyclin proteins
 The cyclins and the cyclin
dependent kinases
(enzymes) control the
different stages of the cell
cycle. The cyclins bind to
the CDK’s.
 The stop lights represent
quality control checkpoints.
If all is clear, and there are
no cell issues (abnormal
DNA, etc.), a cell is allowed
to continue to develop and
reproduce.
CH. 9.3 – CELL CYCLE
REGULATION
Answer
the following questions…
What
do you think happens if a
checkpoint fails?
What
if a cell is not adequate or is
abnormal and is allowed to
reproduce?
CH. 9.3 – CELL CYCLE REGULATION
CH. 9.3 – CELL CYCLE
REGULATION
Cancer
Uncontrolled
growth and
division
Failure of the cell
cycle regulation
Failure of the
immune system
Crowds out
normal cells
killing the
organism
CH. 9.3 – CELL CYCLE
REGULATION
Causes of cancer –
carcinogens and
genetics
Carcinogens –
environmental factors
and substances that
cause mutations in
DNA that lead to
cancer. (Cigarettes,
radiation, UV sunlight
exposure)
Cancer caused by
exposure to
carcinogens is
preventable.
Mutations
in DNA are completely
random.
The more exposure to carcinogens
the more the mutations occur.
If cancer runs in a family, the rate of
mutation is high and it is essential to
avoid carcinogens to reduce the
risk of cancer.
CH. 9.3 – CELL CYCLE REGULATION
Apoptosis – programmed cell death.
Protects organisms from cancerous growths.
Allows death of cells that are too damaged to repair.
Ex. Leaves of plants turning color and falling in autumn
CH. 9.3 – CELL CYCLE REGULATION
CH. 9.3 – CELL CYCLE
REGULATION
Stem cells – are unspecialized
cells…Adult and Embryonic
Have not picked a specific job
yet
Can be encouraged through
stem cell research to become a
specific cell (brain cell, heart
cell, nerve cell)
Adult stem cells are mainly
used for repairing tissue.
Stem cell research controversy.
Using embryonic stem
cells…what are the
issues/ethics involved for using
embryonic stem cells as
opposed to adult stem cells?
 TASKS!
 List
all of the ways that the cell cycle
prevents mutated cells from reproducing.
 Discuss fully what cancer is and what
causes it.
 Discuss why stem cell research is important
and the possible medical applications that
this research could bring.
CH. 9.3 – CELL CYCLE REGULATION