The Cell CycleChapter 2, Lesson 1

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?

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

Left SideDraw 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 Different for different cells

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.

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

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.

Left Side: Write/Pair/Share Predicit: Do ALL cells go through

interphase?

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.

Mitosis Four main phases

Prophase Metaphase Anaphase Telephase

More about this later . . .

Different cells at different times