Cell Division—Mitosis Why don’t our cells just get bigger and bigger? Answer: Our cells can’t handle that much waste material passing through them. Cells increase in number – Not size. Cell Division: One cell divides into two cells – these are identical to the parent cell. Cell division has 6 phases. Mitosis has 4 phases.

Phase One - Interphase Inter means “between” No actual dividing taking place. Fat chromosomes become thin, threadlike CHROMATIN. In animal cells CENTRIOLES, or leaders appear. Toward end of interphase, chromosomes duplicate. What was 46 is now 92. Now called sister chromatids and are connected by a centromere. Look at the board for an example of interphase. Draw and label it in your notes.

Phase Two - Prophase Mitosis begins! Process by which nucleus of a cell divides into 2 nuclei and formation of 2 new daughter cells begins. Chromatin back to chromosomes. Nucleolus disappears. Centrioles begin moving. Nuclear membrane breaks down. Spindle forms. (Bridge) Draw out prophase.

Phase 3 - Metaphase Centromeres line up in the middle. Then attach to the spindle.

Phase 4 - Anaphase Centromeres (holding sister chromatids together) split. Move apart to separate ends of the cell. Called chromosomes again.

ANAPHASE

Phase 5 - Telophase Chromosomes uncoil into thin chromatin. Nuclear membrane forms. Mitosis is COMPLETE!

TELOPHASE

Phase 6 - Cytokinesis Cytoplasm divides Cell membrane moves inward to Pinch cytoplasm in two Each cell now contains a nucleus with identical chromosomes. 2 new daughter cells END RESULT== **In plant cells-a cell plate forms in between—this will become the Cell Wall

The 6 “phases” of Cell Division Phase One – Phase Two – Phase Three – Phase Four – Phase Five – Phase Six – Interphase Prophase Metaphase Anaphase Telophase Cytokinesis I Painted My Aunt’s Toes Crimson!! Now you come up with your own way! MITOSISMITOSIS