Mitosis and the Cell Cycle Cell reproduction Discussion Questions 1) 2) 3) 4) 5) 6) What are the two main phases that occur during the cell cycle? What are Interphase, Mitosis, and Cytokinesis? Why is Interphase so important? Create a unique mneumonic device to remember what occurs during each step of Mitosis. How is Cytokinesis different in plant cells and animal? Create a question about this topic that you don’t know. The Cell Cycle The sequence of growth and division of a cell. 95% of cell cycle in interphase 5% of cell cycle in mitosis Animated Mitosis Cycle • Interphase • Prophase • Metaphase • Anaphase • Telophase & Cytokinesis Cell Cycle 5 Interphase occurs before mitosis begins • • Chromosomes are copied (# doubles) Chromosomes appear as threadlike coils (chromatin) at the start, but each chromosome and its copy(sister chromosome) change to sister chromatids at end of this phase Nucleus CELL MEMBRANE Cytoplasm Interphase Animal Cell Plant Cell Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm Prophase 1st step in Mitosis • • • Mitosis begins (cell begins to divide) Centrioles (or poles) appear and begin to move to opposite end of the cell. Spindle fibers form between the poles. Sister chromatids Centrioles Spindle fibers Prophase Animal Cell Plant Cell Spindle fibers Centrioles Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm Metaphase 2nd step in Mitosis • Chromatids (or pairs of chromosomes) attach to the spindle fibers. Centrioles Spindle fibers Metaphase Animal Cell Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm Plant Cell Anaphase 3rd step in Mitosis • Chromatids (or pairs of chromosomes) separate and begin to move to opposite ends of the cell. Centrioles Spindle fibers Anaphase Animal Cell Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm Plant Cell Telophase 4th step in Mitosis • • • Two new nuclei form. Chromosomes appear as chromatin (threads rather than rods). Mitosis ends. Nuclei Chromat in Nuclei Telophase Animal Cell Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm Plant Cell Cytokinesis occurs after mitosis • Cell membrane moves inward to create two daughter cells – each with its own nucleus with identical chromosomes. Animal Mitosis -- Review Interphase Prophase Metaphase Anaphase Telophase Interphase Plant Mitosis -- Review Interphase Prophase Metaphase Anaphase Telophase Interphase Remembering the steps in mitosis. https://www.youtube.com/watch?v=PMXatafIXc I - not very "I"nteresting. P - chromosomes first a"P"pear M - chromosomes line up in "M"iddle A - they move "A"way T - you have "T"wo (in mitosis) I Played My Accordion Today. Cell Cycle and Mitosis Research Questions 1) 2) 3) 4) 5) What are the two main parts of the cell cycle? Describe the state of a cell about to start mitosis How is the genetic material in two daughter cells similar to the genetic material in a parent cell? Describe in order the steps that occur during mitosis and cytokinesis and their major changes that occurs. How is cytokinesis in plant cells similar to cytokinesis in animal cell? How is it different? Answers Interphase and Mitosis are the two main parts of the cell cycle 2) Before Mitosis the cell is in interphase and is in the process of copying the DNA and making extra organelles for both cells. 3) In the parent cell the genetic information is copied and the daughter cells receive a full set of the same DNA. 1) Answers 4) Interphase: DNA is copied and organelles produced Prophase: Centrioles and spindle fibers form. Centrioles move to poles Metaphase: DNA line up in middle of cell and spindle fibers attach to centrioles and DNA. Anaphaase: The DNA is pulled to different sides Telophase: New nuclei form around the DNA. Cytokinesis: The membranes in an animal splinch off forming two cells. In plant cells a new cell wall forms in the middle of the parent cell dividing the daughter cells. Answers 5) Both plant and animal cells go through cytokinesis which is the process by which the cell membrane/wall separate the cytoplasm forming two new cells. They are different because in an animal cell the cell membrane splinch off forming two cells. In plant cells a new cell wall forms in the middle of the parent cell dividing the daughter cells.