What if yourhair never
grew back after a
haircut?
Hair grows by producing new cells at the
root to replace old ones.
Why do you think your body needs to
constantly produce new cells?
3.
Lesson
Objective
s Define thecell cycle.
By the end of this lesson, you
will:
Explain the sequence of events in
the eukaryotic cell cycle.
Identify and describe the key phases
of mitosis.
Differentiate between cytokinesis in
plant and animal cells.
4.
THE CELL CYCLE
Thisprocess describes how eukaryotic cells
grow, replicate their DNA, and divide.
There are two main parts:
Interphase
M-phase
(Cell growth & DNA Replication)
(Cell division)
5.
PARTS OF THECELL CYCLE
Interphase
M-phase
This is the longest
phase of the cell
cycle, where the cell
grows and prepares
for division.
This is the phase
where cell division
occurs.
By the end, two
daughter cells are
formed and the
cycle starts again.
It is divided into:
G1 phase
S phase
G2 phase
6.
Checkpoint
G1 PHASE THEGROWTH PHASE
What happens?
The cell grows in size, producing proteins and
organelles essential for the next stages of the
cell cycle.
It ensures the cell is large enough, has
sufficient energy, and is ready to begin DNA
replication.
01
7.
Checkpoint
S PHASE DNAREPLICATION
What happens?
The cell duplicates its DNA, creating two
identical copies of each chromosome.
It verifies that DNA replication is complete and
checks for any errors in the newly synthesized
DNA.
02
8.
G2 PHASE QUALITYCONTROL
The cell continues to grow and synthesizes
molecules like microtubules needed for
division.
It detects and repairs DNA damage, ensuring
the cell is ready to proceed to mitosis.
03 Checkpoint
What happens?
9.
M PHASE CELLDIVISION
The cell enters the final stage of its cycle to
divide and form two new daughter cells.
Mitosis: The nucleus divides into two identical
nuclei.
Cytokinesis: The cytoplasm splits, resulting in
two separate daughter cells.
04 Components
What happens?
Check for
Understanding
WHAT COULDHAPPEN IF THE
DNA DOESN’T COPY
ACCURATELY DURING THE S
PHASE?
If the DNA isn't copied properly, the
daughter cells could end up with missing
or extra genetic material.
This could cause conditions like Down
syndrome or other genetic disorders.
12.
MITOSIS
This process showshow a cell’s
nucleus divides, ensuring that each
new cell receives an identical set of
chromosomes.
ANAPHASE
THE SEPARATION
Sister chromatidsare pulled apart
to opposite poles by spindle fibers.
Each chromatid is now considered
an individual chromosome.
0
3
Key Events:
CYTOKINESIS
The cytoplasm dividesas the cell membrane
pinches inwards, eventually separating the
cell into two daughter cells.
Each daughter cell receives a full set of
organelles and a nucleus, completing the
division process.
THE FINAL DIVIDE
