Mitosis and stem cells

• What are chromosomes?

  DNA molecules that carry a large number of genes
• What is mitosis?

  Cell division that generates new cells for growth and repair. The division of one cell into two genetically identical daughter cells
• What happens during a cell cycle.

  The genetic material is doubled and then divided into two identical cells.
• What is stage 1 of the cell cycle?

  The cells grow and increase the numbers of sub cellular structures

  The dna replicates to form two copies of each chromosome
• What is stage 2 of the cell cycle

  mitosis - one set of chromosomes is pulled to each end of the dividing cell and the nucleus divides
• What is stage 3 of the cell cycle

  cytoplasm and cell membrane divide to form 2 identical daughter cells
• Why is mitosis important?

  important in the growth and development of multicellular organisms
• What is a stem cell?

  An undifferentiated cell that can differentiate to become any type of specialised cell
• What is the function of stem cells in embryos

  can be cloned

  made to differentiate into most different types of human cells.
• What is the function of stem cells in bone marrow

  Can form many types of cells including blood cells
• What is the function of stem cells in the meristem of plants

  The plants can differentiate into any type of plant cell throughout the life of the plant
• What conditions can stem cells help with

  Diabetes and paralysis
• What happens in therapeutic cloning

  An embryo is produced with the same genes as the patient
• What is a major benefit of therapeutic cloning

  No rejection so stem cells from the embryo can be used for medical treatment
• What are the risks of using stem cells

  transfer of viral infection, and some people have ethical or religious objections
• What is important about cloning plants using stem cells

  Rare species can be cloned to protect from extinction

  Crop plants with special features such as disease resistance can be cloned to produce large numbers of identical plants for farmers