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Mitosis is a vital process in the cell cycle that leads to cell division, resulting in two identical daughter cells. Key terms include chromosomes, chromatin, and chromatids. During prophase, chromosomes condense, and the nuclear envelope breaks down. Metaphase aligns chromosomes at the cell equator, while anaphase separates sister chromatids. Telophase sees the formation of a new nuclear membrane and uncoiling of chromosomes. The process culminates in cytokinesis, where the cytoplasm divides. Each phase of mitosis is crucial for cellular replication and growth.
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Some Terms You Need to Understand • Chromosome– long strand of DNA • Chromosomes condense at the beginning of Mitosis • DNA will wrap around histones, which condenses it.
DNA andhistones SupercoiledDNA DNA doublehelix Chromatin Chromosome Structure
Condensed, duplicated chromosome A Few More Terms • Chromatin—When DNA wraps around histones, what is formed is called a chromatin. • Chromatid– 1 half of a duplicated chromosome. • Centromere • telomere
The Beautiful Process Called The Cell Cycle • Interphase prepares the cell to divide • Time for duplication of organelles and DNA replication • 2 full sets of DNA that are large enough to divide • G1, Synthesis, G2 • G1—after cell division, matures and grows, makes cytoplasm and organelles, carries out normal functions • S—DNA replication • G2—makes all structures needed to survive
Cell Division in Prokaryotes • Prokaryotes have no nucleus • Divide asexually by binary fission • Chromosome (circular) copies itself and becomes 2x the original size • Cell wall forms between chromosomes and parent cell splits in two • Results in 2 identical daughter cells
Cell Division in Eukaryotes • MITOSIS!!!!!!!!!!!!!!!!!!!!!!!
Mitosis • PMAT • Prophase—chromatin condenses to chromosome. • Nuclear envelop breaks down, nucleolus disappears, centromeres and centrioles start to migrate to opposite sides • Spindle fibers grow from centrioles and radiate to center of cell.
PMAT • Metaphase– spindel fibers attach to protein structure on centromere • Align chromosome along the equator of cell
PMAT • Anaphase—sister chromatids separate • Spindle fibers begin to shorten • This pulls sister chromatids away from each other • They move to opposite sides of the cell
PMAT • Telophase—complete set of identical chromosomes are at each pole of the cell • Nuclear membrane starts to form • Chromosomes start to uncoil • Spindle fibers fall apart
The Final Part • CYTOKINESIS—divides cytoplasm into 2 cells and goes through the cycle again.
