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• cell division is the process by which a parent cell divides into
• in cell division the cell that is dividing is called "parent" cell and the parent cell divides into two "daughter" cells
• the process repeats in what is called the cell cycle
• for the "Growth" and "development" of our body
• to "repair" the dead and damaged "tissues"
• for "reproduction
• mitosis: the process that cells use to make exact "replicas" of themselves is "mitosis". Mitosis is observed in all the body's cell including "eyes", "skins", "hair" and "muscle" cells
• meisos: the type of cell division where "sperm" or "egg" cells are produced with "haploid" set of chromosomes instead of identical "daughter" cells as in mitosis
• G0 Phase ("Resting phase") the cell "neither divides "nor" prepares itself for the division
• G1 Phase ("Gap 1") the cell is "metabolically" active and "Grows" continuously during this phase
• S phase (Synthesis) the "DNA" replication or synthesis occurs during this phase
• G2 Phase ("Gap 2"): "Protein" synthesis happens in this phase
• 1st -Prophase

  2nd -Metaphase

  3rd-Anaphase

  4th-Telaphase

  Followed by "cytokinesis"
• where chromosomes condense
• Spindle fibers form
• Chromosomes are captured by spindle
• chromosomes align along equator of the cell with one kinetochore facing each pole
• spindle fibers attached to kinetochores shorten and pull the chromatids towards the opposite polls
• the cell appears almost oval
• sister chromatids separate from eachother
• spindle fibers between the poles disintegrate
• the nuclear envelops start reforming
• chromosomes revert to their extended state by absorbing water
• appears a constriction in the cytoplasm
• cytokinesis complete the enclosing of each daughter nucleus into a seperate cell
• meiosis is a form of cell divison that produces haploid sex cells or gametes (1 copy of chromosomes)
• in meiosis each new cell contains a unique set of genetic information
• after meiosis the sperm and egg cells acan join to create a new organism
• Meiosis have 2 cycles of cell division

  Meiosis I

  Meiosis II
• Meiosis I halves the number of chromosomes and is also when crossing over happens
• the end result is four daughter cells called haploid cells
• Meiosis II halves the amount of genetic information in each chromosome of each cell
• haploid cells only have one set of chromosomes
• in meiosis I a special cell division reduces the cell from diploid to haploid
• Prophase I

  the homologous chromosomes pair and exchange DNA to form recombinant chromosomes
• Leptotene: chromosomes start to condense
• Zygotene: homologous chromosomes start becoming closely associated ( sypnasis) to form pairs of chromosomes obivalents consisting of four chromatids (tetrads)
• Patchytene

  crossing over between prairs of homologous chromosomes to form chiasmata
• diplotene

  homologous chromosomes start to sepereate but remain attached by the chiasmata
• dianises: homologous chromosomes start to continue to sepereate and chiasmata move to the ends of the chromosomes