Download The Cell Cycle - Jefferson School District

The Cell Cycle
Chapter 2, Lesson 1
A big question for something so little!
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You start life as a single cell!!
You will have a trillion cells!!
SO . . .
 How are all these cells made?
 How long does a cell live?
The Cell cycle
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Cell cycle = the life cycle of a cell
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Just like all living things, our CELLS have a cycle of
life.
Phases of cell cycle
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Interphase
Mitosis
Cytokinesis
Birth/Childhood
Teenager
Leaving your parents
Left Side
Draw Figure 1 from page 88 in your notebook.
Use Color
Predict: What phase is the longest?
Interphase, Mitosis, or Cytokinesis. Explain.
Length of Cell Cycle
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Different for different cells
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Zebra Fish:
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Skin = 24 hours
Brain = never finishes, stays
in Interphase.
From 1 cell to hatching in 48
hours.
Sea Urchin
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From 1 cell to 4 in 2 hours.
First is Interphase
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When a cell is getting ready to reproduce.
The longest phase.
The chromosomes in the nucleus look like a
bunch of thin spagehetti because they are
getting ready to be copied.
Interphase has 3 phases = G1, S, G2
The Phases of Interphase
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G1 – Growth and regular cell functions.
S – Growth and the chromosomes make
copies of themselves and the NUCLEUS
makes copy.
G2 – Growth and cell functions. All the
organelles make copies of themselves.
Left Side: Write/Pair/Share
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Predicit: Do ALL cells go through
interphase?
Left Side – Answers
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Muscles, nerve, brain and red blood cells do
NOT reproduce. Injuries to these can be
permenant. The cells don’t leave interphase.
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Drugs literally kill brain cells. . . You can’t
get them back.
Mitosis
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Four main phases
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Prophase
Metaphase
Anaphase
Telephase
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More about this later . . .
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Different cells at different times