omosis

• Osmosis


  The diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane
• Dilute solution


  • Contains a high concentration of water
  • Contains a low concentration of solute (e.g. sugar)
• Concentrated solution


  • Contains a low concentration of water
  • Contains a high concentration of solute (e.g. sugar)
• Osmosis


  Water diffuses from the dilute solution to the concentrated solution through a partially permeable membrane
• Animal cell in water

  Water moves into the cell by osmosis, causing the cell to expand and potentially burst
• Animal cell in concentrated solution


  Water moves out of the cell by osmosis, causing the cell to shrink
• Plant cell in water

  Water moves into the cell by osmosis, causing the cell to become turgid (swollen)
• Plant cell in concentrated solution

  Water moves out of the cell by osmosis, causing the cell to become flaccid (shrunken)
• The cell wall prevents the plant cell from bursting when water moves in by osmosis
• Mitosis


  The process of cell division that produces two genetically identical daughter cells
• Cell cycle involving mitosis

  • DNA replication to form two copies of each chromosome
  • Chromosomes pulled to each end of the cell
  • Nucleus divides
  • Cytoplasm and cell membrane divide to form two identical cells
• Body cells contain 23 pairs of chromosomes
• Gametes have unpaired chromosomes
• Chromosomes


  Carry a large number of genes that determine many of our features
• Animals and plants contain a very large number of cells
• Cells can divide by either mitosis or meiosis
• Mitosis is the focus of this video
• Functions of mitosis


  • Essential for growth and development of multicellular organisms
  • Repairs damaged tissues
  • Occurs during asexual reproduction