THE CELL CYCLE

Producing new BODY cells allows you to: 1. Grow 2. Replace dead cells Ex: Stomach so acidic that cells lining must be replaced every few days! The Life of a Cell

Cell Cycle – life cycle of a cell Begins – when cell is formed Ends – when cell divides and forms new cells The Life of a Cell

a. chromatids – two copies of a duplicated chromosome b. centromere – center region that holds chromosomes together Making More Eukaryotic Cells

The Life of a Cell

Mitosis – 4 stages plus a beginning and an end : Interphase – Beginning stage Prophase Metaphase Anaphase Telophase Cytokinesis – Ending stage Cell Cycle

 Longest phase  G1 or Gap 1: The cell grows  S or Synthesize: DNA duplicates or copies  G2 or Gap 2: The cell grows again and prepares for mitosis Interphase

1.Interphase – before mitosis: Interphase

Prophase – 1 st phase of mitosis  DNA chromatin condense into X- shaped chromosomes  nuclear membrane breaks apart  centrioles (spindle structures) move to opposite side of cell and send out spindles (spider webs) MITOSIS

Metaphase – 2 nd phase of mitosis  doubled chromosomes line up in middle of cell MITOSIS

Anaphase – 3 rd phase of mitosis  doubled chromosomes separate  single chromosomes move to opposite sides MITOSIS

Telophase – 4 th stage of mitosis  chromosomes reach the centriole  new nuclear membrane forms MITOSIS

Cytokinesis – last stage of cell division  cytoplasm divides and cell membrane pinches together in middle to form two daughter cells Cytokinesis

 Parent cell divides and produces TWO daughter cells identical to the original Making More Eukaryotic Cells