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Cell Cycle and Mitosis

The life of a cell is amazingly complex. Mitotic cell division requires precision and organization to ensure that both daughter cells receive EXACTLY the same genetic material. But how? This video explains the phases of the cell life cycle, the important structural features of chromosomes and a whole lot about microtubules which organize the whole affair. The end of the video briefly discusses how often cells divide and how they "know" when to divide - and what happens when they make mistakes. Want more? Subscribe:    / thepenguinprof   FB Page:   / thepenguinprof   Twitter:   / penguinprof   Web: http://www.penguinprof.com/ --------------------------------------------------------------------------------------------------------------------- VIDEO DETAILS The Cell Cycle and Mitosis Cell Division is needed for: Reproduction in single-celled organisms Asexual growth in colonial organisms Development in multicellular organisms from a fertilized egg Cell replacement in multicellular organisms Challenges of Cell Division When one cell divides into two, the daughter cells must be IDENTICAL to the parent cell DNA management is key Each human cell (excluding eggs or sperm) holds DNA containing 6 billion base pairs with approximately 50,000 protein-encoding genes That DNA, if stretched out, would be 6 feet in length Chromatin vs. Chromosome MISCONCEPTION ALERT Replication of DNA does NOT occur during mitosis! It has to occur BEFORE mitosis begins!!! This is Your (Cell's) LIFE The Cell Cycle Interphase: G1, S, G2 Cell Division: Mitosis, Cytokinesis A Little More About Chromosomes: centromere, sister chromatids, kinetochore Moving Chromosomes Around: centrosome (spindle poles), astral microtubules, kinetochore microtubules The Cell Cycle Prophase Chromatin condenses into chromosomes Nucleolus disappears Microtubule assembly begins Prometaphase Nuclear membrane breaks down Kinetochore microtubules form and attach to kinetochores Polar microtubules push against each other and push the centrosomes apart Astral microtubules assemble to anchor the centrosomes at opposite poles Metaphase Chromosomes line up on the metaphase plate Anaphase Chromosomes break at the centromere into sister chromatids Sister chromatids move toward opposite poles Telophase Chromatids (now called daughter chromosomes) begin to decondense into chromatin Nuclear membranes begin to form around each set of daughter chromosomes New cell wall begins to form (plants) Cleavage furrow forms (animals) Cleavage (why the fascination?) Plants and Cell Wall Formation How Often do Cells Divide? When Things Go Wrong... Cancer