cell cycle

• Cell cycle


  A series of events that takes place in a cell as it grows and divides
• Cell cycle

  1. Interphase

  2. Mitosis
• Cell division


  Division of a cell into two daughter cells with the same genetic material
• Wounds in a matter of days heal due to cell division
• Cytokinesis


  The physical process of cell division, which divides the cytoplasm of a parental cell into two daughter cells
• Meiosis


  A type of cell division that reduces the number of chromosomes in the parent cell by half and produces four gamete cells
• Cytokinesis is the physical process of cell division, which divides the cytoplasm of a parental cell into two daughter cells
• interphase- preparatory stage / longest stage / lasts 90% total time required for cell cycle
• interphase - chromosomes duplication and cell growth / very high metabolic activity
• G1 – first gap / gap between cell division and dna sythesis

  =increase in the supply of proteins
• Synthesis – cells makes a copy of the dna in its nucleus, process is called replication
• G2 – spans from completion of DNA synthesis to the start of actual cell cycle / the cell produces structures that it will use to divide
• cell division - Division of a cell into two daughter cells with the same genetic material
• Cells divide in two basic stages:

  *Mitosis and *Cytokinesis
• Cell cycle


  The lifespan of a eukaryotic somatic cell
• Somatic cell


  Any cell in the body of an organism except for sex cells such as sperm and egg cells
• Cell cycle

  1. Cell growth

  2. Cell division
• Interphase


  The state a cell spends most of its life in
• Phases of interphase

  • G1
  • S
  • G2
• G1 phase


  Cell is busy growing and carrying out its function
• Some cells such as muscle and nerve cells exit the cell cycle after G1 because they do not divide again
• S phase


  Cell makes a copy of its DNA
• G2 phase


  Cell undergoes further preparations for cell division
• M phase


  1. Mitosis (nuclear division)

  2. Cytokinesis (division of the cytoplasm)
• At the end of M phase, you have two daughter cells identical to each other and identical to the original cell
• Phases of the cell cycle

  • G1
  • S
  • G2
  • M
• Most cell growth and function happen during G1
• The cell enters the S phase when it needs to divide
• In G2, the cell undergoes further preparations for cell division
• The M phase consists of mitosis and cytokinesis
• • Prophase - formation of spindle /  significant changes also occurs in both the nucleus and cytoplasm
• some of the microtubules emerging from centrioles reach the highly condensed chromosomes and attch to the protein structure - kinetochore
• Telophase-formation of two daughter nuclei
• anaphase - the centromere of each chromosome divides and the two sister chromatids detach from each other
• meiosis - reduces the number of chromosomes
• haploid cell - cell containing a single set of chromosomes
• when four chromosomes are lined up together, it is called a tetrad
• crossing over results in the exchange of genes