Chapter 2

• Adult stem cell


  Undifferentiated cell that can develop into one or more types of specialised cell
• Binary fission


  Cell division in bacteria
• Cell cycle


  Series of stages that body cells go through to divide and form two identical daughter cells
• Chromosome


  Contains a large number of genes made of DNA molecules
• Clone


  Genetically identical copy of an organism
• Daughter cells


  Two identical cells formed by cell division
• Embryonic stem cell


  Stem cell from an early human embryo that can differentiate into any specialised cell type
• Gene


  Unit of heredity located on a chromosome
• Meristem


  Region of rapid cell division in the tips of plant roots and shoots
• Mitosis


  Cell division process that produces two genetically identical daughter cells
• Nucleus


  Contains the chromosomes in a cell
• Therapeutic cloning


  Using a patient's own cells to create an early embryo clone, then using stem cells from the embryo to treat the patient's medical conditions
• Adult stem cells


  • Found in specific parts of the body in adults and children
  • Can only differentiate into certain types of specialised cells
• Embryonic stem cells


  • Found in early human embryos
  • Can differentiate into any type of specialised cell
• Plant meristems


  • Found in the roots and shoots of plants
  • Can differentiate into all plant cell types
  • Used to clone whole plants
• Cell cycle


  1. Stage 1: cell grows bigger, DNA replicates

  2. Stage 2 (mitosis): chromosomes pulled to each end, nucleus divides

  3. Stage 3: cytoplasm and cell membrane divide to form two daughter cells
• Chromosomes are made of DNA molecules and are normally found in pairs in normal body cells
• In binary fission, bacteria can multiply as often as every 20 minutes in optimum conditions
• In therapeutic cloning, stem cells from a cloned embryo are used to treat the patient as they have the same genes
• Mitosis is used for growth, repair, and asexual reproduction