The cell cycle notes 5.1
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5.1 The Cell Cycle KEY CONCEPT Cells have distinct phases of growth, reproduction, and normal functions. What does it mean for a cell to be immortal?
Transcript of The cell cycle notes 5.1
5.1 The Cell Cycle
KEY CONCEPT Cells have distinct phases of growth, reproduction, and normal functions.
What does it mean for a cell to be immortal?
5.1 The Cell Cycle
Cells double their DNA in order to divide and create two nearly identical duplicates or copies.
Divide – to separateDuplicate – an identical copyDouble – to increase twofoldCopy – a reproduction of an original
5.1 The Cell Cycle
The cell cycle has four main stages.
– Gap 1 (G1): 2. cell growth and normal functions, double organelles
– DNA synthesis (S): 4. copies DNA, Replication
– Gap 2 (G2): 6. additional growth, normal functions
• The main stages of the cell cycle are
5.1 The Cell Cycle
The cell cycle has four main stages.• The main stages of the cell cycle
• Take out a textbook and turn to
CH 5.1 – page 134
Copy down the diagram (just
like the one to the right) and
make sure to take detailed notes
on what happens in each part of
the cell cycle!
5.1 The Cell Cycle
Cells divide at different rates.
• The rate of cell division varies with the need for those types of cells.
• Some cells are unlikely to divide (G0).
5.1 The Cell Cycle
Cell size is limited.
• Volume increases faster than surface area.
5.1 The Cell Cycle
• Surface area must allow for adequate exchange of materials.
– Too small, not enough machinery– Too big, nutrients and waste can’t move in/out– Cell growth is coordinated with division.– Cells that must be large have unique shapes.
5.1 The Cell Cycle
• Mitosis occurs only if the cell is large enough and the DNA undamaged.
– Interphase– Mitosis (M): Cell division
includes division of the cell nucleus (mitosis) and division of the cell cytoplasm (cytokinesis)
– Prophase– Metaphase– Anaphase– Telophase– cytokinesis
5.1 The Cell Cycle
• What are the four main parts of the cell cycle?• What phase are cells in during the majority of
their life span?• Why is surface area to volume ratio important for
cells?• Why would some cells have a shorter life cycle
than others?• Are there cells that rarely or never divide?
