Cell Division: Mitosis vs. Meiosis

Prophase = DNA condenses into X shaped structures called chromosomes Metaphase = Chromosomes align in the middle of the cell Anaphase = Sister chromatids separate and move towards opposite poles Telophase = Chromosomes reach the poles and nuclear envelope reforms

Semi-conservative replication = Formation of two DNA helices, each with one old and one new strand Cytokinesis = Division of the cytoplasm to form two separate cells Chromatids = Two identical DNA molecules that make up a chromosome Mitosis = Cell division process resulting in two daughter cells with identical genetic material

Nucleus = Contains genetic material and controls cell activities Centrioles = Help in organizing spindle fibers for chromosome movement Spindle fibers = Assist in separating sister chromatids during cell division Cytoskeleton = Provides structural support and aids in cell shape maintenance

<p>Chromosome = Thread-like structure composed of DNA and protein that carries genetic information Nucleotide = Basic building block of DNA consisting of a sugar, phosphate, and nitrogenous base Helicase = Enzyme responsible for unwinding the double-stranded DNA helix during replication Replication fork = Y-shaped region where parental DNA strands are separated for replication</p> Signup and view all the answers

<p>Cells at the end of mitosis have 46 chromosomes each. = Resulting daughter cells have the same number of chromosomes as the parent cell Cytokinesis occurs after mitosis. = Division of cytoplasm to complete cell division process Prophase is characterized by condensed chromosomes. = DNA condenses into visible structures called chromosomes in this stage Anaphase is when sister chromatids separate. = Chromatids split and move towards opposite poles during this phase</p> Signup and view all the answers

<p>Metaphase = Chromosomes line up end to end along the center of the cell and spindle fibres attach to each chromatid Anaphase = The two sister chromatids are pulled apart to opposite sides of the cell Telophase = The chromatids gather together on opposite poles and two new nuclear membranes begin to form Cytokinesis = Cytoplasm separates into two new cells and the reformation of the cell membrane</p> Signup and view all the answers

<p>Purpose of meiosis (compare with mitosis) = Creating new sperm or egg cells (Only occurs in ovaries and testes) What is created? = Cell divides into 4 new cells instead of 2 produced by mitosis Also occurs after DNA is replicated and organelles doubled = Meiosis There are two PMAT divisions in meiosis = Meiosis</p> Signup and view all the answers

<p>DNA replication occurs in interphase before mitosis or meiosis begins chromosomes that contain the DNA are sorted in the PMAT steps cytokinesis occurs to divide up the cytoplasm and the organelles within it = Mitosis Each daughter cell has 23 chromosomes instead of 46 (in humans) = Meiosis Cell divides into 4 new cells instead of 2 produced by mitosis = Meiosis Purpose is creating new sperm or egg cells (Only occurs in ovaries and testes) = Meiosis</p> Signup and view all the answers

<p>Metaphase = Chromosomes lining up along the center of the cell Anaphase = Separation of sister chromatids to opposite sides of the cell Telophase = Gathering of chromatids on opposite poles and formation of new nuclear membranes Cytokinesis = Division of cytoplasm into two new cells</p> Signup and view all the answers

<p>In both: DNA replication occurs in interphase before mitosis or meiosis begins chromosomes that contain the DNA are sorted in the PMAT steps cytokinesis occurs to divide up the cytoplasm and the organelles within it = Mitosis There are two PMAT divisions in meiosis = Meiosis Cell divides into 4 new cells instead of 2 produced by mitosis = Meiosis Each daughter cell has 23 chromosomes instead of 46 (in humans) = Meiosis</p> Signup and view all the answers

<p>Creating new sperm or egg cells (Only occurs in ovaries and testes) = Purpose of meiosis (compare with mitosis) Cell divides into 4 new cells instead of 2 produced by mitosis = What is created? Also occurs after DNA is replicated and organelles doubled = Meiosis There are two PMAT divisions in meiosis = Meiosis</p> Signup and view all the answers

<p>DNA helicase = Breaks hydrogen bonds to unzip double helix DNA ligase = Seals breaks in the sugar-phosphate backbone DNA polymerase = Joins free-floating nucleotides with exposed bases Complementary base pairing = Pairs up nucleotides with exposed bases</p> Signup and view all the answers

<p>Mitosis = Cell division for growth or repair Meiosis = Cell division in reproductive organs to produce sperm and egg cells Interphase = Cell spends 90% of its life performing designated function between divisions Cell division trigger = Can be triggered by size due to surface area volume ratio</p> Signup and view all the answers

<p>Hydrogen bonds = Hold DNA strands together (A-T has two bonds, C-G has three) Sugar-phosphate backbone = Sealed by DNA ligase after replication is completed Double helix = Structure of DNA that unzips during replication Nucleotides = Join exposed bases on DNA strands during replication</p> Signup and view all the answers

<p>DNA helicase = Breaks hydrogen bonds to initiate unzipping of DNA strands DNA ligase = Seals breaks in sugar-phosphate backbone after replication is complete DNA polymerase = Joins nucleotides with exposed bases during complementary base pairing Complementary base pairing = Pairs up nucleotides with exposed bases on DNA strands</p> Signup and view all the answers

<p>Cells for growth or repair = Mitosis Production of sperm and egg cells = Meiosis 90% of cell life spent in interphase = Interphase Cell division triggered by size increase = Cell division trigger</p> Signup and view all the answers

<p>DNA unzipping by breaking hydrogen bonds = Step 1 Complementary base pairing of nucleotides = Step 2 Replication completion with sealing of breaks = Step 3 Joining of unattached nucleotides to DNA strand = Step 2</p> Signup and view all the answers