CELL CYCLE
Look both ways
before you cross
the street
H2 O (Water)
See eye to eye
CELL CYCLE
Target: I will be able to identify and describe the main stages of
the cell cycle.
Cell Division: the process when a cell divides into two
daughter cells.
Why do cells divide?
1. To get materials, such as food, water, oxygen, and
waste in and out of the cell efficiently.
2. So DNA can make enough proteins to run the cell.
Pg. 97
Cell Cycle: Process of one cell dividing to become two
cells.
Occurs in Somatic Cells – body cells.
Each cell will have the same genetic information.
Main Stages: Interphase, Mitosis, Cytokinesis.
1. Interphase: a period of cell growth and DNA
replication for all cells.
G1: The cell grows in size so it can divide into two.
The chromosomes are single stranded.
Chromosomes condense in the nucleus.
S: Synthesis of
DNA.
The cell stops
growing.
Chromosomes
replicate,
become double
stranded.
G2: The cell grows
new organelles.
The cell
prepares to
divide.
2. Mitosis: Division of the Nucleus.
3. Cytokinesis: Division of the cytoplasm.
Plant Cytokinesis: The cell builds a cell plate
between the two nuclei that will become the new cell
wall for each cell.
Animal Cytokinesis: The cell cleaves (pinches) in the
middle and becomes two distinct cells.
Cyclins: Proteins that regulate the timing of the cell cycle.
Cyclins make sure that there is not uncontrolled cell
growth.
Without cyclins, the uncontrolled growth leads to cancer
or a tumor.
Summary:
MAIN STAGES OF THE CELL CYCLE
G1(Interphase)
S(Interphase)
G2(Interphase)
Draw pictures to represent what is happening in each stage of
interphase (G1, S, and G2), Mitosis and Cytokinesis. Then draw a
picture to represent the role of cyclins in the cell cycle.
*Use a minimum of 4 colors
Mitosis
Cytokinesis
Cyclins
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