1. The Cell Cycle
Chapter 2, Lesson 1

2. A big question for something so little!
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?

3. The Cell cycle Cell cycle = the life cycle of a cell
Just like all living things, our CELLS have a cycle of life.
Phases of cell cycle
Interphase Birth/Childhood
Mitosis Teenager
Cytokinesis Leaving your parents

4. Left Side Draw Figure 1 from page 88 in your notebook. Use Color
Predict: What phase is the longest?
Interphase, Mitosis, or Cytokinesis. Explain.

5. Length of Cell Cycle Different for different cells Zebra Fish:
Skin = 24 hours
Brain = never finishes, stays in Interphase.
Zebra Fish:
From 1 cell to hatching in 48 hours.
Sea Urchin
From 1 cell to 4 in 2 hours.

6. First is Interphase 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

7. The Phases of Interphase
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.

8. Left Side: Write/Pair/Share
Predicit: Do ALL cells go through interphase?

9. Left Side – Answers
Muscles, nerve, brain and red blood cells do NOT reproduce. Injuries to these can be permenant. The cells don’t leave interphase.
Drugs literally kill brain cells You can’t get them back.

10. Mitosis Four main phases Prophase Metaphase Anaphase Telephase
More about this later . . .

11. Different cells at different times