Cell division and stem cells

• What is mitosis used for?

  • Growth
  • Repair of damaged tissue
• When does cell division occur?

  • An organism grows
  • Organisms need to be replaced with worn-out cells
  • Organisms need to repair damaged tissue.
• Is mitosis haploid or diploid?

  Diploid
• Is meiosis haploid or diploid?

  Haploid
• Cells grow then divide by mitosis only when we need them. When a cell becomes cancerous, it begins to grow and divide uncontrollably. New cells are produced even if the body doesn't need them.
• A group of cancerous cells produces a growth called a tumour.
• Carcinogens cause cancer by damaging DNA which will cause mutations. A single mutation won't cause cancer - several are required.
• How many daughter cells does mitosis prodcue?

  2
• How many chromosomes does a daughter cells of mitosis have?

  46
• Mitosis produces genetically identical daughter cells
• What is a zygote?

  A fertilised egg cell.
• What is meiosis used for?

  • To make sex cells - gametes
• Meiosis produces genetically varied daughter cells
• They divide once and their daughter cells have 46 chromosomes then they divide into 4 and their daughter cells have 23 chromosomes.
• What are stem cells?

  They are undifferenced cells that can turn into any other cells
• Where can stems cells be found in?

  • Embryos
  • Bone marrow in adults
  • Brain
  • Help grow organisms
• What can stems cells be used for?

  • Type 1 diabetes
  • Sclerosis
  • Spinal cord or brain injury
• Embryonic stem cells can differentiate into a wider of variety of stem cells but are difficult to obtain.
• Adult stem cells will differentiate into a narrower range of stem cells.
• What are the benefits on using your own stem cells?

  • No rejection
  • No need to find a donor
  • No need for tissue typing
• What are the ethical issues to stem cells?

  • Embryos being killed
• What are the clinical issues to stem cells?

  • Mutations have been observed in stem cells cultured for a long time and some behave like cancer cells
• What are the social issues to stem cells?

  • Educating the public on what stem cells can do and can't is important
• What are stem cells found in plants?

  Meristem
• The main meristems are close to the top of the shoot and tip of the root
• What is haploid?

  1 set of every 23 chromosomes
• What is diploid?

  2 sets in every type of chromosomes