DNA: Directs cell activity Gene: a segment of DNA that transmits information. Chromosome: a single DNA molecule and its associated proteins. Chromatid: copy of a chromosome.

Mitosis 2012

Centromere – area where the chromatids of a chromosome are attached Mitosis - General Division of the cell nucleus Chromosomes have replicated & are visible # of centromeres = # of chromosomes Centromere – area where the chromatids of a chromosome are attached

Mitosis – General Cont’d 4. Each daughter cell receives its own copy of the parent cell’s DNA 5. Occurs in body cells – somatic cells

Interphase G1 Phase the cell grows & carries out routine functions. (increase in size) S Phase DNA is duplicated/copied. G2 Phase Cell prepares for mitosis. Cell grows & produces additional organelles & cytoplasm.

Interphase Plant Cell Animal Cell Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm

are present in this cell? Prophase How many chromatids are present in this cell? Chromatin condenses and forms chromosomes. Pairs of sister chromatids are joined at the centromere. Nuclear membrane breaks down and disappears. Centrioles (in animal cells) split and move toward opposite poles of the cell. A spindle forms fibers that organize themselves around the centrioles and attach themselves to the centromere. Spindle Fibers are thread-like structures (microtubles) that help separate chromosomes during mitosis .

Prophase Plant Cell Animal Cell Spindle fibers Centrioles Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm

about the spindle fibers and chromosomes? Metaphase Chromosomes line up at the equator of the cell. Each centromere is connected to a spindle fiber. What do you notice about the spindle fibers and chromosomes? They are attached to the centromeres.

Metaphase Plant Cell Animal Cell Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm

Anaphase Sister chromatids separate at the centromere & are pulled by spindle fibers to opposite ends of the cell. Now they again chromosomes.

Anaphase Plant Cell Animal Cell Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm

Telophase Chromosomes gather at opposite ends of cell. Begin to unravel…back to chromatin! Nuclear membrane and nucleolus reform Mitosis is now complete! All the remains is the division!

Telophase Plant Cell Animal Cell Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm

Cytokinesis Daughter Cells Not part of mitosis. Cytoplasm divide in half. Each daughter cell has an identical set of chromosomes Plants – cell plate separates the two new cells Animals – cleavage furrow pinches the two new cells a part; centrioles double Daughter Cells

Animal Mitosis -- Review Interphase                                                              Prophase                                                              Metaphase                                                              Anaphase                                                              Telophase                                                             

Plant Mitosis -- Review Interphase                                                              Prophase                                                              Metaphase                                                              Anaphase                                                              Telophase