Presentation on theme: "KEY CONCEPT Cells divide during mitosis and cytokinesis."— Presentation transcript:
1KEY CONCEPT Cells divide during mitosis and cytokinesis.
2One half of a duplicated chromosome is a chromatid. One long continuous thread of DNA coiled around histones (proteins) is called chromatin.chromatidcentromeretelomereCondensed, duplicated chromosomeOne half of a duplicated chromosome is a chromatid.Sister chromatids are held together at the centromere.Telomeres protect DNA and do not include genes.
3Chromosomes condense at the start of mitosis. DNA wraps around proteins (histones) that condense it.DNA double helixDNA and histonesChromatinSupercoiled DNA
41.Interphase prepares the cell to divide. B. Mitotic Phase- Mitosis and cytokinesis produce two genetically identical daughter cells.Parent cellcentriolesspindle fiberscentrosomenucleus withDNA1.Interphase prepares the cell to divide.DNA is duplicated.
5Cell structures and mitosis Centrosomes-organelle that is the main microtubule organizing center.Aster-cellular star shaped structure that forms around the centrosome-made of microtubulesEquator-mid section of the dividing cellCleavage furrow - indentation that begins the formation of the new cell membraneCell plate- the new cell wallKinetorchore fibers- attachment points on the centromere where the chromosomes are held together to make an XSpindle- fibers that separate the chromosomesMicrotubules-hollow, protein fibers and rods.Cytokinesis-division of the cytoplasm results two daughter cells.
62.During prophase, chromosomes condense, nuclear membrane, nucleus, and nucleolus disappear, spindle fibers form, centrioles make spindle fibers
73.During metaphase- spindle fibers randomly align sister chromatids in the middle of the cell (equator)
84.During anaphase- spindle fibers retract and pull the sister chromatids opposite sides of the cell (poles)
106.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