Mitosis and Cell Division

The Cell Cycle As eukaryotic cells grow and divide, they pass through a cell cycle that consists of 3 stages: Interphase Mitosis (cell division) Cytokinesis (cell division)

The length of time to complete a cell cycle is different for different types of cells: Embryonic cells divide rapidly Adult nerve cells may never divide

Stage 1: Interphase Interphase is the longest stage of the cell cycle The cell performs its normal functions and, in preparation for cell division, duplicates its genetic material (DNA)

Stage 2: Cell Division - Mitosis Consists of 4 phases: Prophase Metaphase Anaphase Telophase

Mitosis Phase 1:Prophase DNA compacts into visible form as chromosomes Each chromosome contains two strands called sister chromatids. Sister chromatids are held together by a centromere The nuclear membrane breaks down

Mitosis Phase 2: Metaphase Chromosomes line up in the middle of the cell.

Mitosis Phase 3: Anaphase The centromere splits and sister chromatids separate. They are now called daughter chromosomes. They move to opposite ends of the cell, pulled by spindle fibres

Mitosis Phase 4: Telophase Final phase of mitosis. Chromosomes stretch out and are no longer visible. A new nuclear membrane forms around each group of daughter chromosomes.

Stage 3: Cell Division - Cytokinesis Final stage of cell division and cell cycle The cytoplasm divides and two genetically identical cells are formed. In a plant cell, a plate develops into a new cell wall In an animal cell, the cell membrane is pinched off in the centre

I, PMAT C (i, robot clip: http://www.youtube.com/watch?v=s0f3JeDVeEo)