KEY CONCEPT Cells divide during mitosis and cytokinesis.

One half of a duplicated chromosome is a chromatid. One long continuous thread of DNA coiled around histones (proteins) is called chromatin. chromatid centromere telomere Condensed, duplicated chromosome One half of a duplicated chromosome is a chromatid. Sister chromatids are held together at the centromere = center Telomere- at the end of DNA molecules- prevent loss of genes

Chromosomes condense at the start of mitosis. DNA wraps around proteins (histones) that condense it. DNA double helix DNA and histones Chromatin Supercoiled DNA

1.Interphase prepares the cell to divide. B. Mitotic Phase- Mitosis and cytokinesis produce two genetically identical daughter cells. Parent cell centrioles spindle fibers centrosome nucleus with DNA 1.Interphase prepares the cell to divide. DNA is duplicated.

1 .PROPHASE: chromosomes condense, nuclear membrane, nucleus, and nucleolus disappear, spindle fibers form, centrioles make spindle fibers

2. METAPHASE: spindle fibers align sister chromatids in the middle of the cell (equator)

3. ANAPHASE: spindle fibers retract and pull the sister chromatids opposite sides of the cell (poles)

4.TELOPHASE: chromosomes uncoil, nuclear membrane reforms.

Cytokinesis- division of the cytoplasm In animal cells, the membrane pinches closed at a point called cleavage furrow. In plant cells-vacuoles join together and form a cell plate. Result- 2 identical daughter cells with identical copies of genetic material-DNA