Mitosis Study Guide Review What is the purpose of Mitosis? Division of cells to grow, or replace old, diseased, dead or damaged body cells Explain each phase of the cell cycle and draw a picture of what a cell in this phase might look like Interphase Cell Grows DNA is copied Visible nucleus and nucleolus DNA is uncondensed=chromatin Chromosomes are NOT visible Interphase Prophase Visible condensed double-stranded chromosomes/ sister chromatids Centrioles begin to send out spindle fibers Nuclear envelope disappears Prophase Plant Cell Animal Cell Metaphase Double-stranded chromosomes/ Sister chromatids line up in the center of the cell Spindle fibers connect to the centromeres of each chromosome Chromatids are being pulled Metaphase Plant Cell Animal Cell Anaphase Sister chromatids are moving apart= chromatids once split Chromatids are moving towards the poles of the cell Spindle fibers pull the chromatids to the poles Anaphase Plant Cell Animal Cell Telophase New nuclear membrane begins to form around each set of chromatids Cytoplasm begins to divide Chromatids uncoil= chromatin once uncondensed Visible cleavage furrow Spindle fibers disappear Telophase Plant Cell Animal Cell Cytokinesis Cytoplasm divides 2 new daughter cells identical to the parent cell After cytokinesis, cell return to interphase Cytokinesis Plant Cell Animal Cell Explain what happens to the cell’s genetic information during the following parts of the cell cycle Interphase DNA is copied DNA is uncondensed=chromatin Chromosomes are NOT visible Prophase Visible condensed double-stranded chromosomes/ sister chromatids Metaphase Double-stranded chromosomes/ Sister chromatids line up in the center of the cell Chromatids are being pulled Anaphase Sister chromatids are moving apart= chromatids once split Chromatids are moving towards the poles of the cell by means of the spindle fibers Telophase New nuclear membrane begins to form around each set of chromatids Chromatids uncoil= chromatin once uncondensed Cytokinesis 2 new daughter cells With identical DNA within each How do daughter cells produced in mitosis compare to the original cell? The daughter cells are identical to the original (parent) cell. Same function, same internal parts, SAME DNA Explain the relationship that mitosis has with cancer. Cancer is unregulated cell growth and division. How do Chemotherapy drugs used in cancer treatment affect Mitosis? They stop cell division at various stages of the cell cycle ◦ Prevent DNA replication (doxorubicin) ◦ Cross-link with DNA to prevent synthesis (cyclophospliamide) ◦ Blocks cells from making nucleotides (methotrexate) Why does chemotherapy tend to cause side effects like hair loss and gastrointestinal issues? They kill off the rapidly dividing cells of the body kill not only rapidly dividing cancer cells but also cells of the rapidly dividing cells like those that make up hair, bone marrow, and the GI tract Effects are NOT usually permanent What is the difference between a scanning electron microscope and a transmission electron microscope? Scanning Electron Microscope ◦ The entire organism/specimen can be used, but it must be coated in a thin layer of gold atoms ◦ The imaged obtained is a 3 dimensional surface image What is the difference between a scanning electron microscope and a transmission electron microscope? Transmission Electron Microscope ◦ Uses a thin slice of an organism/specimen ◦ Used to study the internal make-up of the specimen Scanning Electron Microscope Images Cat Flea Head Scanning Electron Microscope Images Hypodermic Needle Scanning Electron Microscope Images Staple Through Paper Transmission Electron Microscope Images Cross Section of a Sunflower Plant Cell Transmission Electron Microscope Images Giardia Cysts Transmission Electron Microscope Images Cross Section of Chloroplast in a Leaf How are the pictures they take different? Scanning Electron Microscope Images show… ◦ 3 dimensional images of surface Transmission Electron Microscope Images show… ◦ Internal make-up of the specimen (cross section) What types of problems can occur at each stage of the Mitosis? Prophase: nuclear membrane may not dissolve causing the cell to not be able to go through other stages Metaphase: Chromosomes may not line up, causing an error in the remaining phases Anaphase: Sister chromatids may not split correctly, causing an error in the number of chromosomes at each cell pole Telophase: Chromatids may not unravel, causing the chromatin not to be enclosed in the new nuclear membrane. What might happen to an organism if their cells lost the ability to divide via Mitosis? Once that cell dies then that particular cell would not be able to pass on their DNA. Furthermore, that particular organism would not be able to make new cells after the original parent cell has died Eventually casing the death of that particular organism