The Cell Cycle Chapter 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 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 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.

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