Mitosis

• Binary fission: a single bacterial cell duplicates its genetic material and divides into 2 daughter cells

  •Allows bacteria to rapidly colonize new environments

  • High levels of adaptation to changing conditions

  • Quick and efficient reproduction

  • Asexual
• • Many eukaryotes have linear chromosomes

  -Long coiled DNA molecules

  Genes: discrete segments of coiled DNA molecules

  -Contain instructions for building proteins and regulating cell processes
• Cell cycle: process that provides each new cell with a complete set of chromosomes

  -Replicates its DNA

  -Monitors and directs that final separation of chromosomes

  -Does this all through phases

  • G1, S, G2, and M
• Chromosomes: structure of nucleic acids and protein found in the nucleus, carries genetic information

  
  

  Genes: sequence of nucleotides that form part of a chromosome
• Chromatin: DNA, RNA, and protein material that eukaryotic chromosomes are made of

  Centromeres: region of chromosomes where the microtubules of the spindle attach

  Telomeres: region of repetitive DNA at the end of a chromosome
• 3 divisions of interphase

  • G1 phase: responsible for growth and preparation

  •Cell prepares for DNA replication

  •Acquires resources and structural components

  • S phase: DNA replication

  • G2 phase: final preparations
• S phase: DNA replication

  •Enzymes unzip the DNA double helix

  •Expose underlying genetic code, synthesizes 2 identical copies
• G2 phase: final preparations

  • Double checks the work of the previous stages

  • Checks for errors in the replication process

  • Makes necessary repairs before cell division starts
• Mitosis

  • Goal: proper distribution of chromosomes into daughter cells

  • Chromosomes undergo

  • Condensation

  • Alignment

  • Separation

  • Rearrangement

  • All to preserve genetic integrity and diversity

  • Includes prophase, metaphase, anaphase,and telophase (PMAT)
• Prophase

  • Prepares the compacting and condensing of chromosomes

  • Cell nucleus dissolves

  • Mitotic spindle (protein apparatus) starts to guide the separation of genetic material
• Metaphase

  • Part of the cell cycle that aligns chromosomes along the cell equator

  • Alignment in the middle makes sure that each daughter cell gets and equal genetic amount
• Anaphase

  • Bonds that hold sister chromatids together are broken

  • Separated chromatids are pulled towards opposite poles of the cell

  • Each new cell will get a complete set of chromosomes
• Telophase

  • Cell almost done dividing

  • Starts to remake normal structures

  • Cytokinesis: division of the contents of the cell
• Cancer: disruption in cell growth

  • Uncontrolled growth

  • Impaired DNA repair
• G0: Cells at rest