The cell cycle
By the end of the lesson
Describe the stages of the cell cycle
explain what happens if something goes wrong with the cell
cycle
Starter:
① Why is mitosis important?
② What would happen if mitosis didn’t
take place?
③ Suggest one advantage and one
disadvantage of asexual reproduction.
④ What cells in the body do you think are
not diploid?
⑤ How many parents does a cell that
reproduces by sexual reproduction
have?
⑥ How many parents does a cell that
reproduces by asexual reproduction
have?
Keywords: cytokinesis, cancer, apoptosis
Mitosis and the cell cycle
• Cells divide in a series of stages called the cell
cycle.
• Mitosis is only a small part of the cell cycle.
• Outside of the cell cycle, the cell carries out its
normal functions.
During the cell cycle:
1) a cell needs to grow and increase the
number of sub-cellular structures such
as ribosomes and mitochondria
2) the genetic material is doubled
3) then divided into two identical cells
4) the cytoplasm and cell membranes
divide to form two identical cells
(cytokinesis)
What happens if a cell does not pass a
checkpoint? Why?
If a cell does not pass a checkpoint, one of 2 things
will happen:
1. The cell will stop replication and repair the
damage
2. The cell will undergo apoptosis (the cell will selfdestruct)
The cell does this to prevents a cell that is
damaged beyond repair from going on to divide.
The Cell Cycle
In what phase of the cell
cycles does the following
occur:
① The DNA replication
② The cytokinesis
③ The cell organelles copy
④ The cytoplasm increases
in volume
⑤ The cell has left the cycle
and is carrying out its
normal functions