Mitosis

• briefly give the definition of mitosis?

  cell division that produces genetically identical cells
• what are hte 2 types of cell division in eukaroytes?

  meiosis mitosis
• What happens in mitosis?

  A parent cell divides to produce two genetically identical daughter cells
• What do the 2 genetically identical daughter cells produced contain?

  An exact copy of the DNA of the parent cells
• What is mitosis needed for?

  The growth of multicellular organisms

  Repairing damaged tissues
• What do NOT ALL CELLS KEEP in multicellular organisms?

  in multicellular organisms, not all cells keep their ability to divide. the ones that DO, follow a cell cycel
• what is mitosis part of?

  the cell cycle
• What does the cell cycle consist of?

  A period of cell growth and DNA replication called interphase. Mitosis happens after that
• What is interphase?

  cell growth
• what is interphase subdivided into?

  three separate growth staged, called G1, S, and G2
• What does G1 stand for?

  gap phase 1
• Describe G1?

  Cell grows and new organelles and proteins are made
• What does G2 stand for?

  GAP PHASE 2
• What is S?

  Synthesis
• describe S?

  Cell replicates its DNA , ready to divide by mitosis
• describe gap phase 2?

  cell keeps growing and proteins needed for cell division are made
• what is significant about mitosis?


  the cell cycle starts and ends here:

  sequence= mitosis, g1, s,g2
• how many division stages does mitosis have?

  4
• What is mitosis described as?

  Mitosis is one continuous process, but it is described as a series of division stages- PMAT
• When does interphase happen?

  before mitosis in the cell cycel
• Give the order of stages?

  (i)PMAT
• Describe interphase?

  • cell prepares to divide
  • DNA unravelled and replicated, to double its genetic content
  • Organelles are also replicated so it has spare ones
  • ATP content increase
• what does ATP provide?

  The energy needed for cell division
• Describe prophase?

  • Chromosomes condense (they get shorter and fatter)
  • Centrioles start moving to opposite ends of the cell, forming a network of protein fibres across it called the spindle
  • Nuclear envelope breaks down
  • chromosomes lie free in the cytoplasm
• Describe metaphase?

  • Chromosomes (each with 2 chromatids) line up along middle of cell and become attached to the spindle by their centromere
• Describe Anaphase?

  • Centromeres divide, separating each pair of sister chromatids
  • The spindles contract, pulling chromatids to opposite poles of the spindle, centromere first
  • = Chromosomes appear v-shaped
• Describe telaphase?

  • Chromatids reach opposite poles on the spindle
  • chromatids uncoil and become long and thin again = they are now chromosomes again
  • a nuclear envelope forms around each group of chromosomes so there are now two nuclei
  • cytokinesis
  • there are now two genetically identical daughter cells
  • mitosis is doone and each daughter cell starts interphase , ready for next round of mitosis
• PROPHASE:

  
• METAPHASE:

  
• ANAPHASE:

  
• TELOPHASE:

  
• INTERPHASE:

  
• What is cancer the result of?

  uncontrolled cell division