What does a cell need to do before it divides? Answer the following question in your notebook Importance of the cell cycle? So why are chromosomes important? Read about the Eukaryotic Cell Cycle on page 125 of your textbook and use the information to construct a flow map showing the detailed events of the cell cycle. Be sure to leave some space in your flow map so that we can add information to it when we finish Now, lets read about the Control of the Cell Cycle on pages 126 of your textbook. Working with a partner, add this information to the flow map you just created. Cytokinesis 1 st growth phase. During phase. During this phase the cell this phase the cell is growing and going is growing and going through its normal through its normal metabolic processes. metabolic processes. (its doing what it is meant (its doing what it is meant to do). Muscle cells to do). Muscle cells relaxing and contracting, relaxing and contracting, liver cells filtering liver cells filtering etc... etc... During the S phase, During the S phase, the DNA is being the DNA is being synthesized and replicated synthesized and replicated Centrioles replicate and the cell and the cell prepares to divide prepares to divide Cytokinesis But What About Mitosis and Cytokinesis? a process of cell division that forms two new nuclei, each of which has the same number of chromosomes Get a copy of the Mitosis and Cytokinesis Use the information on pages 128 132 of our textbook as well as any other resources to complete the handout. First and longest phase of mitosis. The nuclear envelope dissolves (goes away), chromatin coils up and condenses to form visible chromosomes. The short second phase of mitosis. The doubled chromosomes become attached to the spindle fibers at their centromeres and move to the equator of the cell. The 3 rd phase of mitosis. During this phase, the centromeres split and the sister chromatids are pulled to opposite poles of the cell by the shortening of the microtubules. The final phase of mitosis. Two distinct daughter cells are formed and the cells begin to separate. This stage is indicated by the formation of a cell plate in plant cells and a cleavage furrow in animal cells. Cell Plate Cleavage Furrow Why is Cytokinesis important? Mitosis guarantees genetic continuity. When mitosis is complete, unicellular organisms remain as single cells, In multicellular organisms cell reproduction results in cells that work together as tissues tissues work together to form organs organs to form organ systems and organ systems form organisms.