Stem Cells in Animals & Plants (OCR Gateway GCSE Biology)

Animal stem cells

• A stem cell is an undifferentiated cell of an organism that is capable of dividing to produce many more cells of the same type (undifferentiated stem cells)
• In addition, depending on which instructions they are given, stem cells can also give rise to other cell types through the process of differentiation
• In animals, there are two broad categories of stem cells
  • Embryonic stem cells are found in early embryos - they have the potential to turn into any kind of cell type
    • This is how an early embryo can develop into a complex multicellular organism 
  • Adult stem cells are only found in certain places (like bone marrow) and can only differentiate into a few different cell types

    • They are predominantly used to maintain and repair damaged cells such in the blood or skin

Animal Stem Cells Table

Plant stem cells

• Plant stem cells occur in meristem tissue which is found in areas that are growing such as roots and shoot tips
• Meristem tissue produces unspecialised cells that can differentiate into any cell type needed by the plant
  • e.g. meristem cells in the roots can differentiate into root hair cells 
• Plant stem cells retain the ability to differentiate into any type of plant cell throughout the life of the plant
• It is possible to use plant stem cells to clone plants with desired characteristics
  • e.g. resistance to certain diseases