Cell Cycle: Mitosis

Cell Cycle: Mitosis Cell cycle image 1 *(Scicuious) 1. Interphase: Long period of the cell cycle between one mitosis and the next. Includes; *(Alberts) I. II. III. 2. G1 phase (Gap 1) - Cellular contents excluding the chromosomes, are duplicated. S phase (DNA Synthesis) - Each of the 46 chromosomes are duplicated by the cell. G2 phase (Gap 2) - The Cell “double checks” the duplicated chromosomes for error, making any needed repair. Mitosis - nuclear/chemical events resulting in two daughter nuclei which have identical genetic material to each other and to the mother cell. *(Michael) I. Prophase - the first stage of mitosis.  The chromosomes condense and become visible  The centrioles form and move toward opposite ends of the cell ("the poles")   II. III. IV. V. The nuclear membrane dissolves The mitotic spindle forms (from the centrioles in animal cells)  Spindle fibers from each centriole attach to each sister chromatid at the kinetochore Metaphase  The Centrioles complete their migration to the poles  The chromosomes line up in the middle of the cell ("the equator") Anaphase  Spindles attached to kinetochores begin to shorten.  This exerts a force on the sister chromatids that pulls them apart.  Spindle fibers continue to shorten, pulling chromatids to opposite poles.  This ensures that each daughter cell gets identical sets of chromosomes. Telophase  The chromosomes decondense  The nuclear envelope forms Cytokinesis  division of the cytoplasm.  Cytokinesis reaches completion, creating two daughter cells *(This usually occurs with mitosis, but in some organisms this is not so.) M-Phase (mitosis + cytokinesis) The events of eukaryotic cell division image 2 *(Alberts)       Vocabulary Centromere: area where sister chromatids are held together. *(n.d.) Chromatid: each of a pair of identical DNA molecules after DNA replication; they are joined at the centromere. *(n.d.) Spindle fibers: fibers that attach to chromosomes and move the chromosomes by pulling homologous chromosomes in opposite directions and pushing the poles apart. *(n.d.) Centrioles: one of a pair of cellular organelles that occur especially in animals, are adjacent to the nucleus, function in the formation of the spindle apparatus during cell division, and consist of a cylinder with nine microtubules arranged peripherally in a circle. *(Mayo Clinic Staff) Microtubules: any of the minute tubules in eukaryotic cytoplasm that are composed of the protein tubulin and form an important component of the cytoskeleton, mitotic spindle, cilia, and flagella. *(Mayo Clinic Staff) Kinetochores: a specialized structure on the centromere to which the microtubular spindle fibers attach during mitosis and meiosis. *(Mayo Clinic Staff) Works cited *Alberts, J. (n.d.). Retrieved from http://www.ncbi.nlm.nih.gov/ books/NBK26869/ *Michael, M. (n.d.). Retrieved from http://www.uic.edu/classes/bios/bios100/ lecturesf04 am/lect16.htm *Mayo Clinic Staff. (n.d.). Retrieved from http://www.nlm.nih.gov/medlineplus/ *(n.d.). Retrieved from http://www2.mcdaniel.edu/Biology/PGclass/ mitosis/vocabulary.htm *Scicurious. (n.d.). Retrieved from http://scientopia.org/blogs/scicurious/2010/ 05/31/cell-cycle-p21-depression-and-neurogenesis-and-in-the-hippocampus/ Practice I: Phases/stages: Mix and Match (Match the phases to the left with what happens at each phase/stage.) A. B. C. D. E. F. Cytokinesis Mitosis G1 G2 S Interphase 1. 2. 3. 4. 5. 6. ____ Includes, G1, S, and G2 phases. ____ The Cell “double checks” the duplicated chromosomes for error, making any needed repair. ____ In this stage, division of the cytoplasm occurs, creating two daughter cells. ____ Each of the 46 chromosome are duplicated by the cell. ____ This stage includes Prophase, Metaphase, Anaphase, Telophase. ____ Cellular contents excluding the chromosomes, are duplicated. Practice II: Label the diagram: A. Interphase D. Anaphase G. M-phase Use the following stages/phases and label the digram B. Cytokinesis C. Telophase E. Prometaphase F. Prophase H. Mitosis I. Metaphase ANSWERS