Mitosis

• Nuclear division that occurs in all body cells, producing two genetically identical diploid (2n) daughter cells, provides genetic stability (no variation) and damaged cells can be repaired by neighbouring cells (same tissue) simply dividing
• Interphase: G_1 -> S -> G_2
• Prophase (longest phase): Condensation of DNA causes chromatids to shorten and thicken, nucleoli and nuclear envelope begin to disappear, centrioles migrate to opposite poles and spindle fibres begin to form
• Metaphase: Chromosomes line up on the equator of the cell, centromere attached to spindle fibres
• Anaphase: The centromeres split and sister chromatids pulled apart towards the poles - each chromosome now consists of one chromatid and these follow the centromere towards the poles
• Telophase: Chromosomes reach the poles and uncoil (uncondense), spindle fibres disintegrate and the centrioles replicate, the nuclear envelopes reform and the nucleoli reappear, immediately followed by cytokinesis
• Cytokinesis (in Animal Cells): Ring of actin filaments form around the equator of the cell, this then tightens to form a cleavage furrow, which splits the cell in two
• Cytokinesis (in Plant Cells): Vesicles move to the equator, line up, and fuse to form two membranes called the cell plate, a new cell wall is laid down between the membranes, which fuses with the existing cell wall
• Yeast is a fungus (single-cellular) and divides by budding; it has to stop all functioning to replicate, the daughter cell grows out as an extension of the parent yeast cell
• Reproduction is the ability to produce a new generation of individuals of the same species, mitosis is asexual so clones will be genetically identical to their parents e.g. yeast budding, amoeba dividing